English verb conjugation
CAN UPTURN

Regular verb: upturn - upturned - upturned

Affirmation

Simple form	V-ing form
I can upturn you can upturn he can upturn we can upturn you can upturn they can upturn	I can be upturning you can be upturning he can be upturning we can be upturning you can be upturning they can be upturning
Perfect	V-ing perfect
I can have upturned you can have upturned he can have upturned we can have upturned you can have upturned they can have upturned	I can have been upturning you can have been upturning he can have been upturning we can have been upturning you can have been upturning they can have been upturning

Negation

Simple form	V-ing form
I can't upturn you can't upturn he can't upturn we can't upturn you can't upturn they can't upturn	I can't be upturning you can't be upturning he can't be upturning we can't be upturning you can't be upturning they can't be upturning
Perfect	V-ing perfect
I can't have upturned you can't have upturned he can't have upturned we can't have upturned you can't have upturned they can't have upturned	I can't have been upturning you can't have been upturning he can't have been upturning we can't have been upturning you can't have been upturning they can't have been upturning

Interrogative form

Simple form	V-ing form
can I upturn? can you upturn? can he upturn? can we upturn? can you upturn? can they upturn?	can I be upturning? can you be upturning? can he be upturning? can we be upturning? can you be upturning? can they be upturning?
Perfect	V-ing perfect
can I have upturned? can you have upturned? can he have upturned? can we have upturned? can you have upturned? can they have upturned?	can I have been upturning? can you have been upturning? can he have been upturning? can we have been upturning? can you have been upturning? can they have been upturning?

Interro-negative form

Simple form	V-ing form
can't I upturn? can't you upturn? can't he upturn? can't we upturn? can't you upturn? can't they upturn?	can't I be upturning? can't you be upturning? can't he be upturning? can't we be upturning? can't you be upturning? can't they be upturning?
Perfect	V-ing perfect
can't I have upturned? can't you have upturned? can't he have upturned? can't we have upturned? can't you have upturned? can't they have upturned?	can't I have been upturning? can't you have been upturning? can't he have been upturning? can't we have been upturning? can't you have been upturning? can't they have been upturning?