male gender | Modal : no | may | might | can | could | shall | should | will | would | must | ought to
English verb conjugation COULD WARN
Regular verb: warn - warned - warned
Affirmation
Simple form
I could warnyou could warn
she could warn
we could warn
you could warn
they could warn
V-ing form
I could be warningyou could be warning
she could be warning
we could be warning
you could be warning
they could be warning
Perfect
I could have warnedyou could have warned
she could have warned
we could have warned
you could have warned
they could have warned
V-ing perfect
I could have been warningyou could have been warning
she could have been warning
we could have been warning
you could have been warning
they could have been warning
Negation
Simple form
I couldn't warnyou couldn't warn
she couldn't warn
we couldn't warn
you couldn't warn
they couldn't warn
V-ing form
I couldn't be warningyou couldn't be warning
she couldn't be warning
we couldn't be warning
you couldn't be warning
they couldn't be warning
Perfect
I couldn't have warnedyou couldn't have warned
she couldn't have warned
we couldn't have warned
you couldn't have warned
they couldn't have warned
V-ing perfect
I couldn't have been warningyou couldn't have been warning
she couldn't have been warning
we couldn't have been warning
you couldn't have been warning
they couldn't have been warning
Interrogative form
Simple form
could I warn?could you warn?
could she warn?
could we warn?
could you warn?
could they warn?
V-ing form
could I be warning?could you be warning?
could she be warning?
could we be warning?
could you be warning?
could they be warning?
Perfect
could I have warned?could you have warned?
could she have warned?
could we have warned?
could you have warned?
could they have warned?
V-ing perfect
could I have been warning?could you have been warning?
could she have been warning?
could we have been warning?
could you have been warning?
could they have been warning?
Interro-negative form
Simple form
couldn't I warn?couldn't you warn?
couldn't she warn?
couldn't we warn?
couldn't you warn?
couldn't they warn?
V-ing form
couldn't I be warning?couldn't you be warning?
couldn't she be warning?
couldn't we be warning?
couldn't you be warning?
couldn't they be warning?
Perfect
couldn't I have warned?couldn't you have warned?
couldn't she have warned?
couldn't we have warned?
couldn't you have warned?
couldn't they have warned?
V-ing perfect
couldn't I have been warning?couldn't you have been warning?
couldn't she have been warning?
couldn't we have been warning?
couldn't you have been warning?
couldn't they have been warning?