I can participate you can participate he can participate we can participate you can participate they can participate
V-ing form
I can be participating you can be participating he can be participating we can be participating you can be participating they can be participating
Perfect
I can have participated you can have participated he can have participated we can have participated you can have participated they can have participated
V-ing perfect
I can have been participating you can have been participating he can have been participating we can have been participating you can have been participating they can have been participating
Negation
Simple form
I cannot participate you cannot participate he cannot participate we cannot participate you cannot participate they cannot participate
V-ing form
I cannot be participating you cannot be participating he cannot be participating we cannot be participating you cannot be participating they cannot be participating
Perfect
I cannot have participated you cannot have participated he cannot have participated we cannot have participated you cannot have participated they cannot have participated
V-ing perfect
I cannot have been participating you cannot have been participating he cannot have been participating we cannot have been participating you cannot have been participating they cannot have been participating
Interrogative form
Simple form
can I participate? can you participate? can he participate? can we participate? can you participate? can they participate?
V-ing form
can I be participating? can you be participating? can he be participating? can we be participating? can you be participating? can they be participating?
Perfect
can I have participated? can you have participated? can he have participated? can we have participated? can you have participated? can they have participated?
V-ing perfect
can I have been participating? can you have been participating? can he have been participating? can we have been participating? can you have been participating? can they have been participating?
Interro-negative form
Simple form
can I not participate? can you not participate? can he not participate? can we not participate? can you not participate? can they not participate?
V-ing form
can I not be participating? can you not be participating? can he not be participating? can we not be participating? can you not be participating? can they not be participating?
Perfect
can I not have participated? can you not have participated? can he not have participated? can we not have participated? can you not have participated? can they not have participated?
V-ing perfect
can I not have been participating? can you not have been participating? can he not have been participating? can we not have been participating? can you not have been participating? can they not have been participating?