I can tickle you can tickle he can tickle we can tickle you can tickle they can tickle
V-ing form
I can be tickling you can be tickling he can be tickling we can be tickling you can be tickling they can be tickling
Perfect
I can have tickled you can have tickled he can have tickled we can have tickled you can have tickled they can have tickled
V-ing perfect
I can have been tickling you can have been tickling he can have been tickling we can have been tickling you can have been tickling they can have been tickling
Negation
Simple form
I can't tickle you can't tickle he can't tickle we can't tickle you can't tickle they can't tickle
V-ing form
I can't be tickling you can't be tickling he can't be tickling we can't be tickling you can't be tickling they can't be tickling
Perfect
I can't have tickled you can't have tickled he can't have tickled we can't have tickled you can't have tickled they can't have tickled
V-ing perfect
I can't have been tickling you can't have been tickling he can't have been tickling we can't have been tickling you can't have been tickling they can't have been tickling
Interrogative form
Simple form
can I tickle? can you tickle? can he tickle? can we tickle? can you tickle? can they tickle?
V-ing form
can I be tickling? can you be tickling? can he be tickling? can we be tickling? can you be tickling? can they be tickling?
Perfect
can I have tickled? can you have tickled? can he have tickled? can we have tickled? can you have tickled? can they have tickled?
V-ing perfect
can I have been tickling? can you have been tickling? can he have been tickling? can we have been tickling? can you have been tickling? can they have been tickling?
Interro-negative form
Simple form
can't I tickle? can't you tickle? can't he tickle? can't we tickle? can't you tickle? can't they tickle?
V-ing form
can't I be tickling? can't you be tickling? can't he be tickling? can't we be tickling? can't you be tickling? can't they be tickling?
Perfect
can't I have tickled? can't you have tickled? can't he have tickled? can't we have tickled? can't you have tickled? can't they have tickled?
V-ing perfect
can't I have been tickling? can't you have been tickling? can't he have been tickling? can't we have been tickling? can't you have been tickling? can't they have been tickling?