English verb conjugation
CAN TREE

Regular verb: tree - treed - treed

Affirmation

Simple form	V-ing form
I can tree you can tree he can tree we can tree you can tree they can tree	I can be treeing you can be treeing he can be treeing we can be treeing you can be treeing they can be treeing
Perfect	V-ing perfect
I can have treed you can have treed he can have treed we can have treed you can have treed they can have treed	I can have been treeing you can have been treeing he can have been treeing we can have been treeing you can have been treeing they can have been treeing

Negation

Simple form	V-ing form
I can't tree you can't tree he can't tree we can't tree you can't tree they can't tree	I can't be treeing you can't be treeing he can't be treeing we can't be treeing you can't be treeing they can't be treeing
Perfect	V-ing perfect
I can't have treed you can't have treed he can't have treed we can't have treed you can't have treed they can't have treed	I can't have been treeing you can't have been treeing he can't have been treeing we can't have been treeing you can't have been treeing they can't have been treeing

Interrogative form

Simple form	V-ing form
can I tree? can you tree? can he tree? can we tree? can you tree? can they tree?	can I be treeing? can you be treeing? can he be treeing? can we be treeing? can you be treeing? can they be treeing?
Perfect	V-ing perfect
can I have treed? can you have treed? can he have treed? can we have treed? can you have treed? can they have treed?	can I have been treeing? can you have been treeing? can he have been treeing? can we have been treeing? can you have been treeing? can they have been treeing?

Interro-negative form

Simple form	V-ing form
can't I tree? can't you tree? can't he tree? can't we tree? can't you tree? can't they tree?	can't I be treeing? can't you be treeing? can't he be treeing? can't we be treeing? can't you be treeing? can't they be treeing?
Perfect	V-ing perfect
can't I have treed? can't you have treed? can't he have treed? can't we have treed? can't you have treed? can't they have treed?	can't I have been treeing? can't you have been treeing? can't he have been treeing? can't we have been treeing? can't you have been treeing? can't they have been treeing?