I means the person who is speaking. If your name is John you don’t say John is happy, you say I am happy.

IF – (conjunction) The word if is used when something is not definite, but might be that way. See DEFINITE & MIGHT.” Please come if you can” means please come on the condition that you are able to come. See CONDITION. “If I had a lot of money I would buy a house.” This means that on the condition that I had a lot of money then I would buy a house.

ILLEGAL – (adjective) means not legal, which means not according to the law. An action that breaks the law is illegal. See LEGAL. “It is illegal to steal.

IMAGE – (noun) 1. An image is a picture of something.” He thought he saw her image through the window, but he was not sure that it was her. She saw her image in the mirror. ” 2. If you say something is an exact image of something then you mean t hat it is an exact copy. “ The twins are almost exact images of each other. ” 3. Pictures in the mind are also called images. “ When he thought of her he got an image of her in his mind.

IMAGINARY – (adjective) means something that does not exist in the world around us, but only exists in the mind of someone. An imaginary thing is not real. See EXIST. He thought he saw a tree in the distance, but when we got there we found nothing. “The tree he thought he saw must have been an imaginary tree.” See IMAGINATION.

IMAGINATION – (noun) is the ability to make pictures in the mind of things which are not actually at the same time present in the world around us. “When he reads a cowboy story he uses his imagination and sees himself riding horses and catching cows because he wants to be a cowboy when he grows to be a man.

IMAGINE – (verb) is the action of using one’s imagination. “Imagine that you are in a train and can see the country go by and hear the noise of the wheels.

IMPORTANCE – (noun) is the word for how important something is. “Children often do not realize the importance of getting a good education. “ This means the same as: Children often do not realize how important it is to get a good education.

IMPORTANT – (adjective) means that something should be done because if it were not done then things will be bad.” It is important to have enough water when you travel through very dry country. “- (The bad thing if you run out of water will be that you die of thirst). “ It is important to get a good education. ” – (The bad thing will be that without a good education it will not be easy to get a good job).

IMPOSSIBLE – (adjective) is the opposite of possible. It means not possible or not able to be done.

IN ADVANCE – (adverb) means before something is meant to be. “Because he was going on holiday in the middle of the month he was paid his money in advance. He usually got paid at the end of the month.

INCENTRE – (noun) See diagram 29.

INCLINATION – (noun) 1. The inclination of one line to another line is the angle between the two lines. See diagram 33. One often means the angle between a line and a horizontal line. 2. If one is referring to Cartesian co-ordinates then the angle o f inclination is measured as shown in diagram 33.

INCLINE – (noun) is another word for a slope. “The old car struggled up the steep incline.” An inclined plane is a flat surface that is at a slope. See diagram 48.

INCLINED TO – (to be inclined to is a verb) If I say I am inclined to being cheerful it means that most of the time you see me I will be cheerful. “The Cape Town winter weather is inclined to be wet.

INCLUDE – (verb) To include means to count in. “ When he counted the number who went to the meeting he included the babies and young children. They did not include me for the party so I had to stay at home. The price” “included the tax.” See diagram 14-II.

INCOME – (noun) means the amount of money that is coming in. “He was happy because he had enough income to pay his monthly expenses. “ Income usually means the amount of money coming in during a known period of time. In the above example the income is the amount of money coming in during a month. You can also speak of weekly income and annual income. See ANNUAL.

INCOME TAX – (noun) is a tax paid to the government based on one’s income. On very low incomes one pays no tax at all and as one’s income rises one pays more and more until with a very high income one pays about half of it in income tax.

INDEFINITE – (adjective) 1. Indefinite means not definite which means not exact.” When asked how many people were coming to the meeting his answer was indefinite because he did not know. “2. It also means not fixed in amount. “ We were given an indefinite amount of time to finish the job. “This means we were given as much time as we needed.

INDEPENDENT – (adjective) 1. Independent means not affected by other things or people. “When asked what he thought about the problem he gave his own independent ideas.” 2. It also means not wanting help from others. “Although she was very old she still wanted to be independent and do everything herself.


INDETERMINATE EQUATION – (noun) An indeterminate equation is an equation with an infinite number of solutions. For example in the equation 4x + y = 2 for any value you give x there will be a corresponding value for y.

INDEX – (noun) The plural of index is indices. 1. Index is another word for exponent. See EXPONENT. See Appendix II.10. 2. Index also means a list of contents of a book with the page numbers for the start of each section or chapter. “He found the page number for chapter 3 in” “the index.” 3. It also means a person’s first finger – (forefinger). “He pointed with his index finger.” 4. It also means a thing that points out or shows. “The cheers of the crowd were an index of their” “enjoyment of the skill of the players.

INEQUALITIES – (noun) are statements of things which are not equal. See STATEMENT. They usually state that one number is greater than another number or that one number is less that another number. The sign <;> is used to mean ‘greater than’. 3 < ;> 2 reads as 3 is greater than 2. The sign << is used to mean ‘less than’. 10 << 12 reads as 10 is less than 12. Note that in both cases the point of the sign is next to the smaller number.

INFINITE – (adjective) means endless or without any limit. “On a clear day the sky seems to be infinite. It also means very large. The oceans contain an infinite amount of water.

INFINITIVE – (noun) is a word used in grammar to describe the form of a verb where there is no person or number. If you say ‘I go’ or ‘they go’ then ‘go’ is not an infinitive form because there is person and number – (I is one person, they are many people). ‘To go’ is the infinitive. In English the word ‘to’ is always used for an infinitive. “To run, to eat, to speak, to see are all infinitives.

INFINITY – (noun) means the condition of being infinite. “When you look at the sky on a clear night there seems to be an infinite distance and you seem to be looking at infinity. “ If you choose a very big number you can always think of a bigger number still and then a bigger number and so on and you will never actually reach infinity. So in maths when you say infinity you mean a number that is big enough for the purpose of what you are doing.

INFLECTION – (noun) 1. The point of inflection is that point on a wavy curve at which the curve changes from curving one way to the opposite way. See diagram 30. 2. In grammar inflection means the change of form of a word. For instance the inflected form of man to give the plural is men. For example many verbs are inflected to form the past tense by the addition of an ‘ed’ onto the end of the verb. For example: hunt & hunted, kill & killed, pour & poured. See your grammar book for more examples of inflections. When a word is inflected the result is called an inflection.

INGREDIENT – (noun) An ingredient is one of the things that go together to make something else. “The ingredients to make ice cream are: water, sugar, milk, cream and fat.” See FORMULA.

INNOCENT – (adjective) is the opposite of GUILTY. See OPPOSITE & GUILTY.

INSOLVENT – (adjective) Running a business is like playing a game where the way to win is to sell what you buy – (or make) for more than all the costs of running the business. If you don’t manage to do this then you will end up by owing more money than you can pay. When the value of everything you have is less than what you owe then you are bankrupt. If on the other hand the value of everything you have is more than everything you owe, but you don’t have enough cash to pay the people you owe then you are insolvent. This could happen because you have too much money tied up in stock. One way of getting out of being insolvent is to borrow money from a bank. A better way is to organize a sale and sell off some of your stock to get the money to pay your bills. “The first sign that he was not able to run his business properly was that he became insolvent. Even though he borrowed some money, about six months later he became bankrupt. ”

INSPECT – (verb) means to look at something closely. “Before he decided to buy the car he inspected it for faults.

INSPECTOR – (noun) An inspector is someone whose job it is to look at some things carefully. A ticket inspector is someone whose job it is to inspect tickets. A traffic inspector is someone whose job it is to watch the traffic and to look for bad drivers.

INSTALMENT – (noun) An instalment is the name of one of the payments when one has agreed to pay for something by paying a small amount each month for a number of months.” I bought this bed for 24 monthly instalments of R10. “You can also have weekly or annual instalments.

INSTITUTION – (noun) An institution is a place that has been built and set up to do a particular thing. A school is an institution for learning, a hospital is an institution for healing, a church is an institution where people praise God.

INSURANCE – (noun) is the amount of money one pays to an insurance company to get protection against fire damage, flood damage, theft or damage to their motor cars. It works like this. A whole lot of people pay a small amount of money each year to the insurance company for damage to their motor cars. The insurance company keeps this money safe, but because a lot of people pay, they save a lot of money. If anyone is unlucky enough to have their car damaged in an accident then they make a claim on the insurance company which takes some of the money to pay for the repairs. This works only because many people pay a small amount and only a few have accidents. The insurance company watches carefully each year how much money they get in and how much money they pay out. If more and more people start to have accidents then the insurance company will ask each car owner to pay a higher insurance the next year. If a person has a car accident he will not be able to get money from the insurance company to pay the repairs if he has not taken out insurance before the accident or has forgotten to pay this years insurance payment. An insurance payment is called an insurance premium.

INSURANCE COMPANY – (noun) See INSURANCE. One can also insure one’s life. This type of insurance is called Life Assurance. Life Assurance is also a good way of saving money. One should speak to an Assurance Company to find out how this works.

INTEGER – (noun) means a whole number. 2 is an integer, but 2,2 is not, nor is 2 1/4 an integer. 1, 2, 3, 20, 556, 1158 are all integers.

INTEGRAL – (adjective) 1. Integral means necessary to make something whole.” The two wheels are integral parts of a bicycle. “2. It also means whole or complete. “ The integral system of a bicycle includes the frame, the handle bars, the pedals and sprockets, the chain, the wheels and so on. “3. Integral calculus in maths has a special meaning. See INTEGRAL CALCULUS. 4. An integral number” “means a whole number – (See INTEGER).” ““1, 5, 22 & 543 are integral numbers. 1/2 and 4/5 are not integral numbers. “““ 5. As a noun integral has the same meaning as an integer, a whole number.

INTEGRAL CALCULUS – (noun) is that part of calculus that is used to calculate the areas between a curve and the axis. See diagram 18A.

INTEGRATE – (verb) 1. Integrate means to make whole or to bring the parts of something together. “When the team learnt to integrate their efforts they were very difficult to beat. “ 2. Integrate also means to make available to people of all races on an equal basis. “The government plan to integrate the use of all public places like parks, schools et “3. In maths integrate means to do the actions of integral calculus.

Integration is a short way of saying ‘doing integral calculus’. He is very good at integration.

INTEREST – (verb) 1. Interest means to catch or hold the attention of. “The birds in the trees interest me.” You could instead say that I am interested in birds. 2. As a noun it has the same meaning. “I show a lot of interest in birds.” 3. If you say he has an interest in that business it means that he owns a part of it. 4. In money, interest has a special meaning. Interest is the return you get when you invest money. See INVEST. It is nearly always expressed as a percentage. See PERCENTAGE & CAPITAL. If you are getting say 8 per cent interest on your money invested at a Building Society then this means that for every R100 you have invested for 1 year you will receive R8 interest. If you want to work out the annual interest on an investment of R2000 at 8 percent this is how you would do it: R2000 X 8/100 = R160. See COMPOUND INTEREST.

INTEREST RATE – (noun) just means how big is the interest. “This year the interest rate is 15%, but next year we expect it to drop to 14%.

INTERIOR – (noun) 1. Interior means the inside of something. “The interior of the house needed painting.” 2. An interior angle is an angle on the inside of a figure. See Diagram 13. An angle has an interior part and an exterior part. See Diagram 5.

INTERJECTION – (noun) An interjection is a part of speech like AH or HURRAH. They are usually followed by an exclamation mark – ( ! ).” Ah! She cried, if only I could go too. ” An interjection and an exclamation are the same. See EXCLAMATION.

INTERNAL – (adjective) means on the inside. It is the opposite of external. The internal measurements of a room will always be less than its external measurements because of the thickness of the walls.

INTERPOLATE – (verb) 1. Interpolate means to insert something new or different between other things or words. “She interpolated her first sentence by adding ‘new’ and making it ‘Many new things will happen this year.’ ” 2. In maths interpolate means to get a value between two known values. See diagram 32.

INTERROGATIVE – (adjective) is a word used in grammar to mean asking a question. Why, when and where are interrogative adverbs.

INTERSECT – (verb) 1. Intersect means to cut across. When two lines cross you say they intersect. They have a common point at the place where they intersect. See COMMON. The place where they intersect is called the intersection or the point of intersection. 2. In everyday life when you talk about an intersection you usually mean the place where two or more streets join. See USUAL. See diagram 3. You can also talk about two railway lines intersecting.

INTO – (preposition) means in the direction of the inside of something. “He came into the room. Pour the water into the bucket. It also means ‘to the condition of’. Water turns into steam when you boil it. ”

INTRANSITIVE VERB – (noun) This is a verb that does not take an object. See VERB & OBJECT. Examples of intransitive verbs are: to seem, to fall, to belong, to go. If you use these verbs in some sentences you will see that they do not take objects. For example you can say I fall down, but you cannot fall something. However many verbs can be used either as transitive verbs or as intransitive verbs. When I hit him he jumped – (intransitive). The dog jumped the fence.(transitive).

INVALID – (noun) 1. Invalid means a person who is weak and sick.” She has been an invalid for many years and sits around in a chair for most of the day”. 2. Invalid when spoken a different way – (ask your teacher) means that something is of n o use or not correct. A cheque that is not signed is invalid. – (This means that a bank will not accept it nor pay anyone money for it)” That argument is invalid because it is not based on the truth.

INVEST – (verb) See INTEREST, COMPOUND INTEREST, CAPITAL, PRINCIPLE. When a person has saved some money he can invest it. Places where you can invest money are banks and building societies. When you invest money you are paid interest. The interest p aid is expressed as a percentage. For example if you get 10% interest per annum – (this means over a period of a year) then after you have invested the money for 1 year you will get paid 10% of your capital. See PER CENT.

INVESTMENT – (noun) is the name for money invested. “He made a good investment by buying that building five years ago. “ It is now worth nearly twice as much as he paid for it. “He made a bad investment in that share which is now only worth half what he paid for it.

IRRATIONAL NUMBER – (noun) An irrational number is a number like Pi because it is composed of a non-terminating – (non ending) and non-repeating decimal. Pi = 3,141592+ . The + indicates that the number will go on for as long as you want it to.

IRREGULAR – (adjective) 1. Irregular means not regular. See REGULAR. It means that something is not the normal way. See NORMAL. “I found his irregular behaviour very rude.” The past of irregular verbs usually are a different form to their present. For example: Today I go, but yesterday I went; today he is, but yesterday he was. – (Today I cross the road, but yesterday I crossed the road – this is regular) 2. Irregular also means not at the usual time.” He sleeps at irregular hours. He goes to bed at 4 am and gets up at 11 am”. 3. Irregular also means not with even timing. “The storm went on for 2 hours with irregular flashes of lightning.” 4. In maths it means that a figure is not symmetrical. See Diagram 9. See SYMMETRICAL.

ISOSCELES – (adjective) Isosceles is used to describe a special triangle. An isosceles triangle is a triangle with 2 sides that are equal and 2angles that are equal. See diagram 12.

ITEM – (noun) 1. An item is the name for one of many different things.” She has 20 items on her shopping list. The 10 items on the bill added up to R110. “2. An item is also the name for a piece of news. “ There were four main news items on the front page of the newspaper.