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