Auxiliary verbs are vital for anyone who wants to sound like a native speaker. We use these constructions all the time to show interest, surprise, disagreement, alarm, and many other emotions. The way they are used may seem very difficult at first, but the rewards are great once this grammar has been learnt by heart. Here are 5 different situations when auxiliary verbs should be used
We use question tags to check information which we aren’t sure about. Only one person is speaking when we use this grammar
Question tag: ‘He doesn’t like sea food, does he?’ or ‘He can swim, can’t he?’
Negative changes to positive. Positive changes to negative. Auxiliary remains in the same tense
We use echo questions as a way of showing interest or surprise in what someone is talking about. These are used in 2 way conversations (unlike question tags)
Echo question: A ‘I don’t like sea food.’ B ‘Don’t you?’ (2 people speaking)
Negative stays negative and positive stays positive. Auxiliary remains in the same tense.
So do I, neither can I
We use so to agree with positive sentences, and neither to agree with negative sentences.
A ‘I don’t like sea food.’ B ‘Neither do I.’
A ‘I can speak German.’ B ‘So can I.’
We use ‘I do/have/can/would’ to disagree with a negative sentence, and ‘I don’t/haven’t/can’t/wouldn’t’ to disagree with a positive sentence:
A ‘I don’t like sea food.’ B ‘I do.’
A ‘I can speak German.’ B ‘I can’t.’
We can use an auxiliary verb to avoid repeating a word or phrase
I wouldn’t go there, but he probably would. (go there)
I don’t like him, but he does. (like him)
I can’t do this, but you can. (do this)
We can use an auxiliary verb to make a sentence stronger. In present simple this means adding ‘do’ or ‘does’ (even though it isn’t a question) and in past simple it means adding ‘did’. You must put stress on the auxiliary when you pronounce it.
We DO use this grammar! I DID finish my homework. She DOES love you!
Here is an English lesson which deals with all the different situations (listed above) when we use auxiliary verbs
And here is a test to see if you understood the information
And some questions in English can be formed without an auxiliary. Here is an explanation.
And here is another test