can contest
Regular verb: contest - contested- contested

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can contest
you can contest
he can contest
we can contest
you can contest
they can contest 	I can be contesting
you can be contesting
he can be contesting
we can be contesting
you can be contesting
they can be contesting	I can have contested
you can have contested
he can have contested
we can have contested
you can have contested
they can have contested	I can have been contesting
you can have been contesting
he can have been contesting
we can have been contesting
you can have been contesting
they can have been contesting	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't contest
you can't contest
he can't contest
we can't contest
you can't contest
they can't contest 	I can't be contesting
you can't be contesting
he can't be contesting
we can't be contesting
you can't be contesting
they can't be contesting	I can't have contested
you can't have contested
he can't have contested
we can't have contested
you can't have contested
they can't have contested	I can't have been contesting
you can't have been contesting
he can't have been contesting
we can't have been contesting
you can't have been contesting
they can't have been contesting	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I contest?
can you contest?
can he contest?
can we contest?
can you contest?
can they contest? 	can I be contesting?
can you be contesting?
can he be contesting?
can we be contesting?
can you be contesting?
can they be contesting? 	can I have contested?
can you have contested?
can he have contested?
can we have contested?
can you have contested?
can they have contested? 	can I have been contesting?
can you have been contesting?
can he have been contesting?
can we have been contesting?
can you have been contesting?
can they have been contesting? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I contest?
can't you contest?
can't he contest?
can't we contest?
can't you contest?
can't they contest? 	can't I be contesting?
can't you be contesting?
can't he be contesting?
can't we be contesting?
can't you be contesting?
can't they be contesting? 	can't I have contested?
can't you have contested?
can't he have contested?
can't we have contested?
can't you have contested?
can't they have contested? 	can't I have been contesting?
can't you have been contesting?
can't he have been contesting?
can't we have been contesting?
can't you have been contesting?
can't they have been contesting?