I could tap-dance you could tap-dance he could tap-dance we could tap-dance you could tap-dance they could tap-dance
V-ing form
I could be tap-dancing you could be tap-dancing he could be tap-dancing we could be tap-dancing you could be tap-dancing they could be tap-dancing
Perfect
I could have tap-danced you could have tap-danced he could have tap-danced we could have tap-danced you could have tap-danced they could have tap-danced
V-ing perfect
I could have been tap-dancing you could have been tap-dancing he could have been tap-dancing we could have been tap-dancing you could have been tap-dancing they could have been tap-dancing
Negation
Simple form
I couldn't tap-dance you couldn't tap-dance he couldn't tap-dance we couldn't tap-dance you couldn't tap-dance they couldn't tap-dance
V-ing form
I couldn't be tap-dancing you couldn't be tap-dancing he couldn't be tap-dancing we couldn't be tap-dancing you couldn't be tap-dancing they couldn't be tap-dancing
Perfect
I couldn't have tap-danced you couldn't have tap-danced he couldn't have tap-danced we couldn't have tap-danced you couldn't have tap-danced they couldn't have tap-danced
V-ing perfect
I couldn't have been tap-dancing you couldn't have been tap-dancing he couldn't have been tap-dancing we couldn't have been tap-dancing you couldn't have been tap-dancing they couldn't have been tap-dancing
Interrogative form
Simple form
could I tap-dance? could you tap-dance? could he tap-dance? could we tap-dance? could you tap-dance? could they tap-dance?
V-ing form
could I be tap-dancing? could you be tap-dancing? could he be tap-dancing? could we be tap-dancing? could you be tap-dancing? could they be tap-dancing?
Perfect
could I have tap-danced? could you have tap-danced? could he have tap-danced? could we have tap-danced? could you have tap-danced? could they have tap-danced?
V-ing perfect
could I have been tap-dancing? could you have been tap-dancing? could he have been tap-dancing? could we have been tap-dancing? could you have been tap-dancing? could they have been tap-dancing?
Interro-negative form
Simple form
couldn't I tap-dance? couldn't you tap-dance? couldn't he tap-dance? couldn't we tap-dance? couldn't you tap-dance? couldn't they tap-dance?
V-ing form
couldn't I be tap-dancing? couldn't you be tap-dancing? couldn't he be tap-dancing? couldn't we be tap-dancing? couldn't you be tap-dancing? couldn't they be tap-dancing?
Perfect
couldn't I have tap-danced? couldn't you have tap-danced? couldn't he have tap-danced? couldn't we have tap-danced? couldn't you have tap-danced? couldn't they have tap-danced?
V-ing perfect
couldn't I have been tap-dancing? couldn't you have been tap-dancing? couldn't he have been tap-dancing? couldn't we have been tap-dancing? couldn't you have been tap-dancing? couldn't they have been tap-dancing?