grammar

present:i can . et au passé:i could ?

[Anglika]

Yes.

[engee30]

Originally Posted by Unregistered

present:i can . et au passé:i could ?

There are only two cases I can think of, in which could can be considered as the past form of the verb can:

1. talking about general ability in the past:

I can cycle. [present]
I could cycle when I was ten. [past]

2. in reported/indirect speech:

She says her parrot can talk. [direct speech]
She said her parrot could talk. [reported speech]

[riverkid]

Originally Posted by engee30

There are only two cases I can think of, in which could can be considered as the past form of the verb can:

1. talking about general ability in the past:

I can cycle. [present]
I could cycle when I was ten. [past]

Even this is not an example of 'could' as the past tense of 'can', Engee. The connection here is not a syntactic one, it is a semantic one. [The Grammar Book: An ESL/EFL Teacher's Course, Second Edition]

All that is happening here is 'could' being used for one of its modal meanings, describing an ability that was present in the past. It isn't referencing a meaning of can and describing any specific past action, which is exactly what a past tense does.

A: I can do this neat trick with my fingers.

[A does the neat trick}

B: He could do that neat trick with his fingers.*

(the asterisk[*] denotes an ungrammatical sentence for the situation)

2. in reported/indirect speech:

She says her parrot can talk. [direct speech]
She said her parrot could talk. [reported speech]

The changing of tenses that occurs for reported speech has nothing to do with any actual change in tense. It is only a change in FORM and English happens to use this "backshift" for one reason and one reason only, to mark speech as indirect reported speech as opposed to direct reported speech.

Brian: I had two pens.

Clearly this is a past tense/past time situation which tells us that Brian no longer has the two pens.

Brian: I have two pens.

Joan: What did Brian say, Tanya?

Tanya: He said that he had two pens.

In Tanya's sentence, the 'had' is only a FORM of the past tense. It doesn't actually describe any past tense, does it? We understand that despite the past tense FORM, Brian has two pens.

In modern English, modal verbs are tenseless auxiliary verbs.

[engee30]

Originally Posted by riverkid

...
In modern English, modal verbs are tenseless auxiliary verbs.
...

I couldn't agree more.

Referring back to the examples I gave - according to some grammars and dictionaries like Oxford or Cambridge, could is still regarded as the past tense form of can. Obviously, could can't be used in every case referring to past abilities of present abilities that are described by can.