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