I can speculate you can speculate she can speculate we can speculate you can speculate they can speculate
V-ing form
I can be speculating you can be speculating she can be speculating we can be speculating you can be speculating they can be speculating
Perfect
I can have speculated you can have speculated she can have speculated we can have speculated you can have speculated they can have speculated
V-ing perfect
I can have been speculating you can have been speculating she can have been speculating we can have been speculating you can have been speculating they can have been speculating
Negation
Simple form
I can't speculate you can't speculate she can't speculate we can't speculate you can't speculate they can't speculate
V-ing form
I can't be speculating you can't be speculating she can't be speculating we can't be speculating you can't be speculating they can't be speculating
Perfect
I can't have speculated you can't have speculated she can't have speculated we can't have speculated you can't have speculated they can't have speculated
V-ing perfect
I can't have been speculating you can't have been speculating she can't have been speculating we can't have been speculating you can't have been speculating they can't have been speculating
Interrogative form
Simple form
can I speculate? can you speculate? can she speculate? can we speculate? can you speculate? can they speculate?
V-ing form
can I be speculating? can you be speculating? can she be speculating? can we be speculating? can you be speculating? can they be speculating?
Perfect
can I have speculated? can you have speculated? can she have speculated? can we have speculated? can you have speculated? can they have speculated?
V-ing perfect
can I have been speculating? can you have been speculating? can she have been speculating? can we have been speculating? can you have been speculating? can they have been speculating?
Interro-negative form
Simple form
can't I speculate? can't you speculate? can't she speculate? can't we speculate? can't you speculate? can't they speculate?
V-ing form
can't I be speculating? can't you be speculating? can't she be speculating? can't we be speculating? can't you be speculating? can't they be speculating?
Perfect
can't I have speculated? can't you have speculated? can't she have speculated? can't we have speculated? can't you have speculated? can't they have speculated?
V-ing perfect
can't I have been speculating? can't you have been speculating? can't she have been speculating? can't we have been speculating? can't you have been speculating? can't they have been speculating?