Teaching about modal verbs can be a very interesting and at the same time offer
difficulties to students. All the auxiliary verbs axcept be, do and have are called modal verbs. The modal verbs are could, can, may, might, must, shall, should, ought, will, would. There are certain verbs or expressions that can be used with the same meaning as modals. These are need, had better, have to, have got to, be able to and used to etc. These can give students difficulties as it can be confusing understand which modals to use for which situation as some of them can have the same meaning.
Modal verbs cannot act on their own in a sentence, they are used to help add meaning and are usually followed by the verb in its base form(apart from ought to, it is the only exception). Modal verbs do not change according to whom is using them and in the third person singular we do not add 's'. To form the neagtive simply add 'not' after the verb 'you should not go tomorrow'. Question form is easily formed by swapping the verb and the subject ' I can go tomorrow ' becomes 'can I go tomorrow?.
Modal verbs are added to verbs to add additional sense to the meaning. The additonal senses they help express is ideas of certainty, possibility, necessity, probability, obligation, permission, ability and advice. The difficulties students face is that some modals are used in the same circumstances and have similar meanings. The difference is in some cases is that modal verbs offer
s of formality. Even though they offer
similar meanings they would be best used in different situations. As for offer
ing difficulty in understanding the differences it is best to let the student experience the different situations to understand fully which modal to use in order to add the correct meaning to the verb and sentence.
One situation requires the use of modal verbs to express probability or certainty that something will happen, has happened or is happening. Modal verbs must, can, should, might can be used to express a degree
of certainty or possibility. For example Linda is coming to dinner but she is late. The situation leads to her friends guessing were she is. Here we can use the modal verbs to express levels of certainty or possibility. One friend says that she must be on her way using 'must' to emphasize a high level of certainty. Should could also be used in this situation as it too expresses a high degree of certainty(must is about 95% and should about 90%). Some of Lindas other friends use might, may, and could. These all represent an unsure degree of certainty( less than 50% with might being the least of the 3), it's to say that Lindas friends are really unsure of Lindas whereabouts. Role playing is a good way to offer
the students the situations necessary for them to be able to use these modal verbs and express these levels of certainty or possibility.
The next situation we can look at is when we want to talk about ability. Here we use the modal verb 'can' or be able to . I can play fooball , I can run fast, I can't swim, I can speak two languages,I am able to speak two languages(can being more popular in usage), here we have examples of how to express ability I can do it or I can't do it. A good enjoyable teaching idea is to express the different types of movement in animals, a bird can fly, a lion can't fly etc. This is a good simple way to help students understand how to express ability on a basic level and is suited to elementary students.
Another example is when we want to ask someones permission when we want to request the use of somethng. This can be expressed by using modal verbs may, might, can, could or would and is determined by the situation in which modal is best to use. May is used when we want to express the most polite way of asking. In this situation the rest all offer
similar meaning but are used when we don't need to be at are most polite when we are among friends or family.
There are a few of the easyier situations for the use of modal verbs. There are many more and a student will come across modal verbs all the way through there learning careers from elementary to advanced which will offer
them new and interesting situations.