“Primary and Modal Auxiliary Verbs”

The first thing that we should know about auxiliary verbs is that they don´t tell us the action in a sentence but they help the main verb in the sentence.

The primary auxiliary ‘DO’ is used in the present simple tense and the past simple tense. We generally use it in questions and negative sentences. For example we say «Do you speak Spanish?» «Yes, I speak Spanish» or «No, I don´t speak Spanish». From these examples you can see that ‘DO’ is used in the question and the negative sentence but it isn´t used in the positive sentence. This is because it is not necessary to say «Yes, I do speak Spanish»; we can simply say «Yes, I speak Spanish».

We can also use it in the past simple tense. For example «Did you close the door?» «Yes, I closed the door» or «No, I didn´t close the door». Just as the present simple only uses ‘DO’ in the question and the negative sentence, the past simple also only uses ‘DO’ in the question and the negative sentence.

The primary auxiliary ‘BE’ is used to form the continuous tenses and the passive voice. For example we say «I am speaking to you now». The word «am» is the first person singular of the auxiliary verb ‘BE’. We can also say «He was eating dinner when we got home». The word «was» is how we use the auxiliary verb ‘BE’ in the third person singular of the past tense. If I say «They will be playing tennis at two o´clock today» the words «will be» communicate the future.

To form the passive voice it is necessary to use the auxiliary verb ‘BE’. For example if I say «the pizza was baked by the chef», the word ‘pizza’ is the subject and the word ‘was’ tells us that the action happened in the past. We form the passive voice by using the verb ‘to be’ and a past participle. Another example of the passive voice is the sentence «the letter is being written by the manager». In this sentence the words «is being» tell us that the action is happening now.

We use the primary auxiliary ‘HAVE’ to form the perfect tenses. These tenses include the present, past and future perfect, the perfect continuous and the perfect conditional tenses. To make a sentence using the present perfect tense we use the word ‘have’ and a past participle, for example «I have watched television all day». To form a perfect continuous sentence we can say «I have been watching television all day» and to form a sentence using the perfect conditional tense we can say «I would have watched television all day».

The ten common modal auxiliary verbs are used to express necessity and possibility. To remind us, the ten common modals are ‘CAN’, ‘COULD’, ‘WILL’, ‘WOULD’, ‘SHALL’, ‘SHOULD’, ‘MAY’, ‘MIGHT’, ‘MUST’ and ‘OUGHT’.

If we say «He might work in a hotel» it means perhaps he works in a hotel. The sentence «I must go to bed now», means that it is necessary for me to go to bed now. If I say «It may rain later» it means that is is possible that it will rain.

Remember that modal auxiliary verbs help verbs to form the meaning of a sentence and they cannot be used as main verbs nor do we put two modals together in a sentence. We cannot say «I will might go to the cinema tonight», we either say «I will go to the cinema tonight» or «I might go to the cinema tonight».

Don´t forget that after an auxiliary verb we use the infinitive without ‘to’. For example we say «I must study», not «I must to study». The only exception to this rule is the modal ‘ought’. For example we say «I ought to study» and not «I ought study».

G. Harman

Download Exercise