English verb conjugation
COULD LECTURE

Regular verb: lecture - lectured - lectured

Affirmation

Simple form	V-ing form
I could lecture you could lecture he could lecture we could lecture you could lecture they could lecture	I could be lecturing you could be lecturing he could be lecturing we could be lecturing you could be lecturing they could be lecturing
Perfect	V-ing perfect
I could have lectured you could have lectured he could have lectured we could have lectured you could have lectured they could have lectured	I could have been lecturing you could have been lecturing he could have been lecturing we could have been lecturing you could have been lecturing they could have been lecturing

Negation

Simple form	V-ing form
I couldn't lecture you couldn't lecture he couldn't lecture we couldn't lecture you couldn't lecture they couldn't lecture	I couldn't be lecturing you couldn't be lecturing he couldn't be lecturing we couldn't be lecturing you couldn't be lecturing they couldn't be lecturing
Perfect	V-ing perfect
I couldn't have lectured you couldn't have lectured he couldn't have lectured we couldn't have lectured you couldn't have lectured they couldn't have lectured	I couldn't have been lecturing you couldn't have been lecturing he couldn't have been lecturing we couldn't have been lecturing you couldn't have been lecturing they couldn't have been lecturing

Interrogative form

Simple form	V-ing form
could I lecture? could you lecture? could he lecture? could we lecture? could you lecture? could they lecture?	could I be lecturing? could you be lecturing? could he be lecturing? could we be lecturing? could you be lecturing? could they be lecturing?
Perfect	V-ing perfect
could I have lectured? could you have lectured? could he have lectured? could we have lectured? could you have lectured? could they have lectured?	could I have been lecturing? could you have been lecturing? could he have been lecturing? could we have been lecturing? could you have been lecturing? could they have been lecturing?

Interro-negative form

Simple form	V-ing form
couldn't I lecture? couldn't you lecture? couldn't he lecture? couldn't we lecture? couldn't you lecture? couldn't they lecture?	couldn't I be lecturing? couldn't you be lecturing? couldn't he be lecturing? couldn't we be lecturing? couldn't you be lecturing? couldn't they be lecturing?
Perfect	V-ing perfect
couldn't I have lectured? couldn't you have lectured? couldn't he have lectured? couldn't we have lectured? couldn't you have lectured? couldn't they have lectured?	couldn't I have been lecturing? couldn't you have been lecturing? couldn't he have been lecturing? couldn't we have been lecturing? couldn't you have been lecturing? couldn't they have been lecturing?