English verb conjugation
COULD MODULATE

Regular verb: modulate - modulated - modulated

Affirmation

Simple form	V-ing form
I could modulate you could modulate she could modulate we could modulate you could modulate they could modulate	I could be modulating you could be modulating she could be modulating we could be modulating you could be modulating they could be modulating
Perfect	V-ing perfect
I could have modulated you could have modulated she could have modulated we could have modulated you could have modulated they could have modulated	I could have been modulating you could have been modulating she could have been modulating we could have been modulating you could have been modulating they could have been modulating

Negation

Simple form	V-ing form
I couldn't modulate you couldn't modulate she couldn't modulate we couldn't modulate you couldn't modulate they couldn't modulate	I couldn't be modulating you couldn't be modulating she couldn't be modulating we couldn't be modulating you couldn't be modulating they couldn't be modulating
Perfect	V-ing perfect
I couldn't have modulated you couldn't have modulated she couldn't have modulated we couldn't have modulated you couldn't have modulated they couldn't have modulated	I couldn't have been modulating you couldn't have been modulating she couldn't have been modulating we couldn't have been modulating you couldn't have been modulating they couldn't have been modulating

Interrogative form

Simple form	V-ing form
could I modulate? could you modulate? could she modulate? could we modulate? could you modulate? could they modulate?	could I be modulating? could you be modulating? could she be modulating? could we be modulating? could you be modulating? could they be modulating?
Perfect	V-ing perfect
could I have modulated? could you have modulated? could she have modulated? could we have modulated? could you have modulated? could they have modulated?	could I have been modulating? could you have been modulating? could she have been modulating? could we have been modulating? could you have been modulating? could they have been modulating?

Interro-negative form

Simple form	V-ing form
couldn't I modulate? couldn't you modulate? couldn't she modulate? couldn't we modulate? couldn't you modulate? couldn't they modulate?	couldn't I be modulating? couldn't you be modulating? couldn't she be modulating? couldn't we be modulating? couldn't you be modulating? couldn't they be modulating?
Perfect	V-ing perfect
couldn't I have modulated? couldn't you have modulated? couldn't she have modulated? couldn't we have modulated? couldn't you have modulated? couldn't they have modulated?	couldn't I have been modulating? couldn't you have been modulating? couldn't she have been modulating? couldn't we have been modulating? couldn't you have been modulating? couldn't they have been modulating?