I could vocalize you could vocalize she could vocalize we could vocalize you could vocalize they could vocalize
V-ing form
I could be vocalizing you could be vocalizing she could be vocalizing we could be vocalizing you could be vocalizing they could be vocalizing
Perfect
I could have vocalized you could have vocalized she could have vocalized we could have vocalized you could have vocalized they could have vocalized
V-ing perfect
I could have been vocalizing you could have been vocalizing she could have been vocalizing we could have been vocalizing you could have been vocalizing they could have been vocalizing
Negation
Simple form
I couldn't vocalize you couldn't vocalize she couldn't vocalize we couldn't vocalize you couldn't vocalize they couldn't vocalize
V-ing form
I couldn't be vocalizing you couldn't be vocalizing she couldn't be vocalizing we couldn't be vocalizing you couldn't be vocalizing they couldn't be vocalizing
Perfect
I couldn't have vocalized you couldn't have vocalized she couldn't have vocalized we couldn't have vocalized you couldn't have vocalized they couldn't have vocalized
V-ing perfect
I couldn't have been vocalizing you couldn't have been vocalizing she couldn't have been vocalizing we couldn't have been vocalizing you couldn't have been vocalizing they couldn't have been vocalizing
Interrogative form
Simple form
could I vocalize? could you vocalize? could she vocalize? could we vocalize? could you vocalize? could they vocalize?
V-ing form
could I be vocalizing? could you be vocalizing? could she be vocalizing? could we be vocalizing? could you be vocalizing? could they be vocalizing?
Perfect
could I have vocalized? could you have vocalized? could she have vocalized? could we have vocalized? could you have vocalized? could they have vocalized?
V-ing perfect
could I have been vocalizing? could you have been vocalizing? could she have been vocalizing? could we have been vocalizing? could you have been vocalizing? could they have been vocalizing?
Interro-negative form
Simple form
couldn't I vocalize? couldn't you vocalize? couldn't she vocalize? couldn't we vocalize? couldn't you vocalize? couldn't they vocalize?
V-ing form
couldn't I be vocalizing? couldn't you be vocalizing? couldn't she be vocalizing? couldn't we be vocalizing? couldn't you be vocalizing? couldn't they be vocalizing?
Perfect
couldn't I have vocalized? couldn't you have vocalized? couldn't she have vocalized? couldn't we have vocalized? couldn't you have vocalized? couldn't they have vocalized?
V-ing perfect
couldn't I have been vocalizing? couldn't you have been vocalizing? couldn't she have been vocalizing? couldn't we have been vocalizing? couldn't you have been vocalizing? couldn't they have been vocalizing?