English verb conjugation
COULD STUDY

Regular verb: study - studied - studied

Affirmation

Simple form	V-ing form
I could study you could study she could study we could study you could study they could study	I could be studying you could be studying she could be studying we could be studying you could be studying they could be studying
Perfect	V-ing perfect
I could have studied you could have studied she could have studied we could have studied you could have studied they could have studied	I could have been studying you could have been studying she could have been studying we could have been studying you could have been studying they could have been studying

Negation

Simple form	V-ing form
I couldn't study you couldn't study she couldn't study we couldn't study you couldn't study they couldn't study	I couldn't be studying you couldn't be studying she couldn't be studying we couldn't be studying you couldn't be studying they couldn't be studying
Perfect	V-ing perfect
I couldn't have studied you couldn't have studied she couldn't have studied we couldn't have studied you couldn't have studied they couldn't have studied	I couldn't have been studying you couldn't have been studying she couldn't have been studying we couldn't have been studying you couldn't have been studying they couldn't have been studying

Interrogative form

Simple form	V-ing form
could I study? could you study? could she study? could we study? could you study? could they study?	could I be studying? could you be studying? could she be studying? could we be studying? could you be studying? could they be studying?
Perfect	V-ing perfect
could I have studied? could you have studied? could she have studied? could we have studied? could you have studied? could they have studied?	could I have been studying? could you have been studying? could she have been studying? could we have been studying? could you have been studying? could they have been studying?

Interro-negative form

Simple form	V-ing form
couldn't I study? couldn't you study? couldn't she study? couldn't we study? couldn't you study? couldn't they study?	couldn't I be studying? couldn't you be studying? couldn't she be studying? couldn't we be studying? couldn't you be studying? couldn't they be studying?
Perfect	V-ing perfect
couldn't I have studied? couldn't you have studied? couldn't she have studied? couldn't we have studied? couldn't you have studied? couldn't they have studied?	couldn't I have been studying? couldn't you have been studying? couldn't she have been studying? couldn't we have been studying? couldn't you have been studying? couldn't they have been studying?