Some additional stuff about modals

[beginner16]

hello


1)
a) I thought WILL could only have the form “WILL + present infinitive”! But in the following sentence WILL is used with perfect infinitive:

“I’m sure you will have noticed that attendance has fallen sharply.”

The main sentence does talk about present/future ( as in “You will notice now or soon” ), but why is PERFECT infinitive used instead of PRESENT infinitive?




2)
a) Past form of CAN is COULD and of WILL is WOULD. Are these verbs actual past forms ( the same way wrote is past form of write ), or does is just mean that when used to describe past, we use COULD/WOULD instead of CAN/WILL?

b)I know that COULD is a past form of CAN when talking about some ability in the past, but what do we use instead of CAN when we want to express a request, an offer or permission that someone gave in the past? Or can in at least some of those cases CAN be used as it is?

c)when COULD is used as a past form of CAN, its form can only be “COULD + present infinitive”, but not COULD + perfect infinitive? If so, why?



3) “He could have sold cars.”
“You could have told me.”

a) The above two sentences can only talk about something in the past and not the present/future?

Thus is the form “COULD + perfect infinitive” used only when talking about something that should be done, but it wasn’t?




4) Perfect present tense has same form as perfect infinitive and yet perfect infinitive is used to talk about actions that happened before another action. Shouldn’t prefect infinitive also be used to describe the same time period as present perfect tense?




5) Among other things we also use present participle for building present continuous and present perfect continuous tenses. Then why couldn’t we also claim that present gerund is used for building those two tenses?

thank you

cheers

[Lucretia]

Hello beginner16,

First of all I'd recommend you a superb grammar book - Practical English Usage by Michael Swan (Oxford University Press). When I bought it, it was a dream come true.
Besides, look here - http://www.longman.com/ (http://www.longman.com/)

1. WILL is used with perfect infinitive to express certainty about past situations (M.Swan p.611):
We can't go and see them now - they'll have gone to bed.
I could add that this usage is typical when you suppose sth has already happened.
You could also use must in the similar meaning:
They must have gone to bed.

2a. Right, past form of CAN is COULD and of WILL is WOULD, the same way wrote is the past form of write.
We use CAN, COULD, WILL and WOULD in many various ways. It would take too long to write about everything.

I've got no more time today, sorry.
Best wishes. :)

[Marius Hancu]

3)
“He could have sold cars.”
“You could have told me.”

a) The above two sentences can only talk about something in the past and not the present/future?

Thus is the form “COULD + perfect infinitive” used only when talking about something that should be done, but it wasn’t?

Only past.

... that should have been done, but it wasn’t.