English verb conjugation
COULD GUESS

Regular verb: guess - guessed - guessed

Affirmation

Simple form	V-ing form
I could guess you could guess she could guess we could guess you could guess they could guess	I could be guessing you could be guessing she could be guessing we could be guessing you could be guessing they could be guessing
Perfect	V-ing perfect
I could have guessed you could have guessed she could have guessed we could have guessed you could have guessed they could have guessed	I could have been guessing you could have been guessing she could have been guessing we could have been guessing you could have been guessing they could have been guessing

Negation

Simple form	V-ing form
I couldn't guess you couldn't guess she couldn't guess we couldn't guess you couldn't guess they couldn't guess	I couldn't be guessing you couldn't be guessing she couldn't be guessing we couldn't be guessing you couldn't be guessing they couldn't be guessing
Perfect	V-ing perfect
I couldn't have guessed you couldn't have guessed she couldn't have guessed we couldn't have guessed you couldn't have guessed they couldn't have guessed	I couldn't have been guessing you couldn't have been guessing she couldn't have been guessing we couldn't have been guessing you couldn't have been guessing they couldn't have been guessing

Interrogative form

Simple form	V-ing form
could I guess? could you guess? could she guess? could we guess? could you guess? could they guess?	could I be guessing? could you be guessing? could she be guessing? could we be guessing? could you be guessing? could they be guessing?
Perfect	V-ing perfect
could I have guessed? could you have guessed? could she have guessed? could we have guessed? could you have guessed? could they have guessed?	could I have been guessing? could you have been guessing? could she have been guessing? could we have been guessing? could you have been guessing? could they have been guessing?

Interro-negative form

Simple form	V-ing form
couldn't I guess? couldn't you guess? couldn't she guess? couldn't we guess? couldn't you guess? couldn't they guess?	couldn't I be guessing? couldn't you be guessing? couldn't she be guessing? couldn't we be guessing? couldn't you be guessing? couldn't they be guessing?
Perfect	V-ing perfect
couldn't I have guessed? couldn't you have guessed? couldn't she have guessed? couldn't we have guessed? couldn't you have guessed? couldn't they have guessed?	couldn't I have been guessing? couldn't you have been guessing? couldn't she have been guessing? couldn't we have been guessing? couldn't you have been guessing? couldn't they have been guessing?