English verb conjugation COULD FASTEN

Regular verb: fasten - fastened - fastened


Affirmation

Simple form

I could fasten
you could fasten
he could fasten
we could fasten
you could fasten
they could fasten

V-ing form

I could be fastening
you could be fastening
he could be fastening
we could be fastening
you could be fastening
they could be fastening

Perfect

I could have fastened
you could have fastened
he could have fastened
we could have fastened
you could have fastened
they could have fastened

V-ing perfect

I could have been fastening
you could have been fastening
he could have been fastening
we could have been fastening
you could have been fastening
they could have been fastening

Negation

Simple form

I could not fasten
you could not fasten
he could not fasten
we could not fasten
you could not fasten
they could not fasten

V-ing form

I could not be fastening
you could not be fastening
he could not be fastening
we could not be fastening
you could not be fastening
they could not be fastening

Perfect

I could not have fastened
you could not have fastened
he could not have fastened
we could not have fastened
you could not have fastened
they could not have fastened

V-ing perfect

I could not have been fastening
you could not have been fastening
he could not have been fastening
we could not have been fastening
you could not have been fastening
they could not have been fastening

Interrogative form

Simple form

could I fasten?
could you fasten?
could he fasten?
could we fasten?
could you fasten?
could they fasten?

V-ing form

could I be fastening?
could you be fastening?
could he be fastening?
could we be fastening?
could you be fastening?
could they be fastening?

Perfect

could I have fastened?
could you have fastened?
could he have fastened?
could we have fastened?
could you have fastened?
could they have fastened?

V-ing perfect

could I have been fastening?
could you have been fastening?
could he have been fastening?
could we have been fastening?
could you have been fastening?
could they have been fastening?

Interro-negative form

Simple form

could I not fasten?
could you not fasten?
could he not fasten?
could we not fasten?
could you not fasten?
could they not fasten?

V-ing form

could I not be fastening?
could you not be fastening?
could he not be fastening?
could we not be fastening?
could you not be fastening?
could they not be fastening?

Perfect

could I not have fastened?
could you not have fastened?
could he not have fastened?
could we not have fastened?
could you not have fastened?
could they not have fastened?

V-ing perfect

could I not have been fastening?
could you not have been fastening?
could he not have been fastening?
could we not have been fastening?
could you not have been fastening?
could they not have been fastening?