I can stretch you can stretch she can stretch we can stretch you can stretch they can stretch
V-ing form
I can be stretching you can be stretching she can be stretching we can be stretching you can be stretching they can be stretching
Perfect
I can have stretched you can have stretched she can have stretched we can have stretched you can have stretched they can have stretched
V-ing perfect
I can have been stretching you can have been stretching she can have been stretching we can have been stretching you can have been stretching they can have been stretching
Negation
Simple form
I can't stretch you can't stretch she can't stretch we can't stretch you can't stretch they can't stretch
V-ing form
I can't be stretching you can't be stretching she can't be stretching we can't be stretching you can't be stretching they can't be stretching
Perfect
I can't have stretched you can't have stretched she can't have stretched we can't have stretched you can't have stretched they can't have stretched
V-ing perfect
I can't have been stretching you can't have been stretching she can't have been stretching we can't have been stretching you can't have been stretching they can't have been stretching
Interrogative form
Simple form
can I stretch? can you stretch? can she stretch? can we stretch? can you stretch? can they stretch?
V-ing form
can I be stretching? can you be stretching? can she be stretching? can we be stretching? can you be stretching? can they be stretching?
Perfect
can I have stretched? can you have stretched? can she have stretched? can we have stretched? can you have stretched? can they have stretched?
V-ing perfect
can I have been stretching? can you have been stretching? can she have been stretching? can we have been stretching? can you have been stretching? can they have been stretching?
Interro-negative form
Simple form
can't I stretch? can't you stretch? can't she stretch? can't we stretch? can't you stretch? can't they stretch?
V-ing form
can't I be stretching? can't you be stretching? can't she be stretching? can't we be stretching? can't you be stretching? can't they be stretching?
Perfect
can't I have stretched? can't you have stretched? can't she have stretched? can't we have stretched? can't you have stretched? can't they have stretched?
V-ing perfect
can't I have been stretching? can't you have been stretching? can't she have been stretching? can't we have been stretching? can't you have been stretching? can't they have been stretching?