Auxiliary verbs always come before main verbs in a verb phrase.
- She was [auxiliary verb] singing [main verb] loudly.
- I have seen many strange things in my life.
- I do know what I am talking about!
- I’m sure that we could help you.
- The doctor will come again tomorrow.
- Do you think that she did not know where they had hidden the money?
Modal auxiliaries come before primary auxiliaries.
- I suppose they could [modal auxiliary] have [primary auxiliary] done [main verb] it.
- Madonna will be appearing on the Parkinson Show next week.
- We would have been here sooner if the traffic had not been so bad.
- But you must have seen her!
- I may have seen her. I’m not sure.
The auxiliary have comes before the auxiliary be.
- What have you been doing?
- I had been working in the garden all day.
- Fortunately, the thieves have been caught by the police.
There can only be one modal verb in a verb phrase. It would NOT be grammatical to say, for example, we will can go tomorrow, since both will and can are modal verbs. Similarly, it would be wrong to say we will must go, since both will and must are modal verbs.
it is, however, sometimes possible to use a lexical verb or a phrase in sentences like these, so making the sentences grammatical:
- We will be able to go tomorrow.
- NOT We will can go tomorrow.
- We will have to go.
- NOT We will must go.
The verbs that form a verb phrase usually stand together in a sentence, but they may sometimes be separated by one or more other words, such as adverbs.
The words in a verb phrase may be separated by adverbs, such as not, -n’t, never, always, often, just or only.
- We did not see anything interesting at all.
- They might not always be able to help you.
- The parcels may not even have arrived yet.
- The boys haven’t done anything wrong.
- I was only trying to help.
- I have never been here before.
- My mother had often warned me not to talk to strangers.
The verb phrase may be split by the words both, all and each:
- You can all come with us.
- The boys are both coming.
- You may each choose a story.
In questions, the verb phrase may be split by the subject of the verb:
- Did you see anything?
- Is she coming here too?
- Has the parcel arrived yet?
- Will you be staying long?
- Will the painters have finished by next week?
The verb phrase may, of course, be split by the subject of the verb and one or more other words:
- Have you ever been here before?
- Are the girls all coming?
- Are they definitely coming?
- Did you two really see a ghost?
- Have the girls only just arrived?
I need to read this again and again