I can collaborate you can collaborate he can collaborate we can collaborate you can collaborate they can collaborate
V-ing form
I can be collaborating you can be collaborating he can be collaborating we can be collaborating you can be collaborating they can be collaborating
Perfect
I can have collaborated you can have collaborated he can have collaborated we can have collaborated you can have collaborated they can have collaborated
V-ing perfect
I can have been collaborating you can have been collaborating he can have been collaborating we can have been collaborating you can have been collaborating they can have been collaborating
Negation
Simple form
I can't collaborate you can't collaborate he can't collaborate we can't collaborate you can't collaborate they can't collaborate
V-ing form
I can't be collaborating you can't be collaborating he can't be collaborating we can't be collaborating you can't be collaborating they can't be collaborating
Perfect
I can't have collaborated you can't have collaborated he can't have collaborated we can't have collaborated you can't have collaborated they can't have collaborated
V-ing perfect
I can't have been collaborating you can't have been collaborating he can't have been collaborating we can't have been collaborating you can't have been collaborating they can't have been collaborating
Interrogative form
Simple form
can I collaborate? can you collaborate? can he collaborate? can we collaborate? can you collaborate? can they collaborate?
V-ing form
can I be collaborating? can you be collaborating? can he be collaborating? can we be collaborating? can you be collaborating? can they be collaborating?
Perfect
can I have collaborated? can you have collaborated? can he have collaborated? can we have collaborated? can you have collaborated? can they have collaborated?
V-ing perfect
can I have been collaborating? can you have been collaborating? can he have been collaborating? can we have been collaborating? can you have been collaborating? can they have been collaborating?
Interro-negative form
Simple form
can't I collaborate? can't you collaborate? can't he collaborate? can't we collaborate? can't you collaborate? can't they collaborate?
V-ing form
can't I be collaborating? can't you be collaborating? can't he be collaborating? can't we be collaborating? can't you be collaborating? can't they be collaborating?
Perfect
can't I have collaborated? can't you have collaborated? can't he have collaborated? can't we have collaborated? can't you have collaborated? can't they have collaborated?
V-ing perfect
can't I have been collaborating? can't you have been collaborating? can't he have been collaborating? can't we have been collaborating? can't you have been collaborating? can't they have been collaborating?