I can buck you can buck he can buck we can buck you can buck they can buck
V-ing form
I can be bucking you can be bucking he can be bucking we can be bucking you can be bucking they can be bucking
Perfect
I can have bucked you can have bucked he can have bucked we can have bucked you can have bucked they can have bucked
V-ing perfect
I can have been bucking you can have been bucking he can have been bucking we can have been bucking you can have been bucking they can have been bucking
Negation
Simple form
I cannot buck you cannot buck he cannot buck we cannot buck you cannot buck they cannot buck
V-ing form
I cannot be bucking you cannot be bucking he cannot be bucking we cannot be bucking you cannot be bucking they cannot be bucking
Perfect
I cannot have bucked you cannot have bucked he cannot have bucked we cannot have bucked you cannot have bucked they cannot have bucked
V-ing perfect
I cannot have been bucking you cannot have been bucking he cannot have been bucking we cannot have been bucking you cannot have been bucking they cannot have been bucking
Interrogative form
Simple form
can I buck? can you buck? can he buck? can we buck? can you buck? can they buck?
V-ing form
can I be bucking? can you be bucking? can he be bucking? can we be bucking? can you be bucking? can they be bucking?
Perfect
can I have bucked? can you have bucked? can he have bucked? can we have bucked? can you have bucked? can they have bucked?
V-ing perfect
can I have been bucking? can you have been bucking? can he have been bucking? can we have been bucking? can you have been bucking? can they have been bucking?
Interro-negative form
Simple form
can I not buck? can you not buck? can he not buck? can we not buck? can you not buck? can they not buck?
V-ing form
can I not be bucking? can you not be bucking? can he not be bucking? can we not be bucking? can you not be bucking? can they not be bucking?
Perfect
can I not have bucked? can you not have bucked? can he not have bucked? can we not have bucked? can you not have bucked? can they not have bucked?
V-ing perfect
can I not have been bucking? can you not have been bucking? can he not have been bucking? can we not have been bucking? can you not have been bucking? can they not have been bucking?