I could shuffle you could shuffle he could shuffle we could shuffle you could shuffle they could shuffle
V-ing form
I could be shuffling you could be shuffling he could be shuffling we could be shuffling you could be shuffling they could be shuffling
Perfect
I could have shuffled you could have shuffled he could have shuffled we could have shuffled you could have shuffled they could have shuffled
V-ing perfect
I could have been shuffling you could have been shuffling he could have been shuffling we could have been shuffling you could have been shuffling they could have been shuffling
Negation
Simple form
I couldn't shuffle you couldn't shuffle he couldn't shuffle we couldn't shuffle you couldn't shuffle they couldn't shuffle
V-ing form
I couldn't be shuffling you couldn't be shuffling he couldn't be shuffling we couldn't be shuffling you couldn't be shuffling they couldn't be shuffling
Perfect
I couldn't have shuffled you couldn't have shuffled he couldn't have shuffled we couldn't have shuffled you couldn't have shuffled they couldn't have shuffled
V-ing perfect
I couldn't have been shuffling you couldn't have been shuffling he couldn't have been shuffling we couldn't have been shuffling you couldn't have been shuffling they couldn't have been shuffling
Interrogative form
Simple form
could I shuffle? could you shuffle? could he shuffle? could we shuffle? could you shuffle? could they shuffle?
V-ing form
could I be shuffling? could you be shuffling? could he be shuffling? could we be shuffling? could you be shuffling? could they be shuffling?
Perfect
could I have shuffled? could you have shuffled? could he have shuffled? could we have shuffled? could you have shuffled? could they have shuffled?
V-ing perfect
could I have been shuffling? could you have been shuffling? could he have been shuffling? could we have been shuffling? could you have been shuffling? could they have been shuffling?
Interro-negative form
Simple form
couldn't I shuffle? couldn't you shuffle? couldn't he shuffle? couldn't we shuffle? couldn't you shuffle? couldn't they shuffle?
V-ing form
couldn't I be shuffling? couldn't you be shuffling? couldn't he be shuffling? couldn't we be shuffling? couldn't you be shuffling? couldn't they be shuffling?
Perfect
couldn't I have shuffled? couldn't you have shuffled? couldn't he have shuffled? couldn't we have shuffled? couldn't you have shuffled? couldn't they have shuffled?
V-ing perfect
couldn't I have been shuffling? couldn't you have been shuffling? couldn't he have been shuffling? couldn't we have been shuffling? couldn't you have been shuffling? couldn't they have been shuffling?