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