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 can't improvise you can't improvise he can't improvise we can't improvise you can't improvise they can't improvise
V-ing form
I can't be improvising you can't be improvising he can't be improvising we can't be improvising you can't be improvising they can't be improvising
Perfect
I can't have improvised you can't have improvised he can't have improvised we can't have improvised you can't have improvised they can't have improvised
V-ing perfect
I can't have been improvising you can't have been improvising he can't have been improvising we can't have been improvising you can't have been improvising they can't 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't I improvise? can't you improvise? can't he improvise? can't we improvise? can't you improvise? can't they improvise?
V-ing form
can't I be improvising? can't you be improvising? can't he be improvising? can't we be improvising? can't you be improvising? can't they be improvising?
Perfect
can't I have improvised? can't you have improvised? can't he have improvised? can't we have improvised? can't you have improvised? can't they have improvised?
V-ing perfect
can't I have been improvising? can't you have been improvising? can't he have been improvising? can't we have been improvising? can't you have been improvising? can't they have been improvising?