I can improvise you can improvise he can improvise we can improvise you can improvise they can improvise
V-ing form
I can be improvising you can be improvising he can be improvising we can be improvising you can be improvising they can be improvising
Perfect
I can have improvised you can have improvised he can have improvised we can have improvised you can have improvised they can have improvised
V-ing perfect
I can have been improvising you can have been improvising he can have been improvising we can have been improvising you can have been improvising they can have been improvising
Negation
Simple form
I cannot improvise you cannot improvise he cannot improvise we cannot improvise you cannot improvise they cannot improvise
V-ing form
I cannot be improvising you cannot be improvising he cannot be improvising we cannot be improvising you cannot be improvising they cannot be improvising
Perfect
I cannot have improvised you cannot have improvised he cannot have improvised we cannot have improvised you cannot have improvised they cannot have improvised
V-ing perfect
I cannot have been improvising you cannot have been improvising he cannot have been improvising we cannot have been improvising you cannot have been improvising they cannot have been improvising
Interrogative form
Simple form
can I improvise? can you improvise? can he improvise? can we improvise? can you improvise? can they improvise?
V-ing form
can I be improvising? can you be improvising? can he be improvising? can we be improvising? can you be improvising? can they be improvising?
Perfect
can I have improvised? can you have improvised? can he have improvised? can we have improvised? can you have improvised? can they have improvised?
V-ing perfect
can I have been improvising? can you have been improvising? can he have been improvising? can we have been improvising? can you have been improvising? can they have been improvising?
Interro-negative form
Simple form
can I not improvise? can you not improvise? can he not improvise? can we not improvise? can you not improvise? can they not improvise?
V-ing form
can I not be improvising? can you not be improvising? can he not be improvising? can we not be improvising? can you not be improvising? can they not be improvising?
Perfect
can I not have improvised? can you not have improvised? can he not have improvised? can we not have improvised? can you not have improvised? can they not have improvised?
V-ing perfect
can I not have been improvising? can you not have been improvising? can he not have been improvising? can we not have been improvising? can you not have been improvising? can they not have been improvising?