I can struggle you can struggle he can struggle we can struggle you can struggle they can struggle
V-ing form
I can be struggling you can be struggling he can be struggling we can be struggling you can be struggling they can be struggling
Perfect
I can have struggled you can have struggled he can have struggled we can have struggled you can have struggled they can have struggled
V-ing perfect
I can have been struggling you can have been struggling he can have been struggling we can have been struggling you can have been struggling they can have been struggling
Negation
Simple form
I cannot struggle you cannot struggle he cannot struggle we cannot struggle you cannot struggle they cannot struggle
V-ing form
I cannot be struggling you cannot be struggling he cannot be struggling we cannot be struggling you cannot be struggling they cannot be struggling
Perfect
I cannot have struggled you cannot have struggled he cannot have struggled we cannot have struggled you cannot have struggled they cannot have struggled
V-ing perfect
I cannot have been struggling you cannot have been struggling he cannot have been struggling we cannot have been struggling you cannot have been struggling they cannot have been struggling
Interrogative form
Simple form
can I struggle? can you struggle? can he struggle? can we struggle? can you struggle? can they struggle?
V-ing form
can I be struggling? can you be struggling? can he be struggling? can we be struggling? can you be struggling? can they be struggling?
Perfect
can I have struggled? can you have struggled? can he have struggled? can we have struggled? can you have struggled? can they have struggled?
V-ing perfect
can I have been struggling? can you have been struggling? can he have been struggling? can we have been struggling? can you have been struggling? can they have been struggling?
Interro-negative form
Simple form
can I not struggle? can you not struggle? can he not struggle? can we not struggle? can you not struggle? can they not struggle?
V-ing form
can I not be struggling? can you not be struggling? can he not be struggling? can we not be struggling? can you not be struggling? can they not be struggling?
Perfect
can I not have struggled? can you not have struggled? can he not have struggled? can we not have struggled? can you not have struggled? can they not have struggled?
V-ing perfect
can I not have been struggling? can you not have been struggling? can he not have been struggling? can we not have been struggling? can you not have been struggling? can they not have been struggling?