can grass
Regular verb: grass - grassed- grassed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can grass
you can grass
he can grass
we can grass
you can grass
they can grass 	I can be grassing
you can be grassing
he can be grassing
we can be grassing
you can be grassing
they can be grassing	I can have grassed
you can have grassed
he can have grassed
we can have grassed
you can have grassed
they can have grassed	I can have been grassing
you can have been grassing
he can have been grassing
we can have been grassing
you can have been grassing
they can have been grassing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I cannot grass
you cannot grass
he cannot grass
we cannot grass
you cannot grass
they cannot grass 	I cannot be grassing
you cannot be grassing
he cannot be grassing
we cannot be grassing
you cannot be grassing
they cannot be grassing	I cannot have grassed
you cannot have grassed
he cannot have grassed
we cannot have grassed
you cannot have grassed
they cannot have grassed	I cannot have been grassing
you cannot have been grassing
he cannot have been grassing
we cannot have been grassing
you cannot have been grassing
they cannot have been grassing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I grass?
can you grass?
can he grass?
can we grass?
can you grass?
can they grass? 	can I be grassing?
can you be grassing?
can he be grassing?
can we be grassing?
can you be grassing?
can they be grassing? 	can I have grassed?
can you have grassed?
can he have grassed?
can we have grassed?
can you have grassed?
can they have grassed? 	can I have been grassing?
can you have been grassing?
can he have been grassing?
can we have been grassing?
can you have been grassing?
can they have been grassing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I not grass?
can you not grass?
can he not grass?
can we not grass?
can you not grass?
can they not grass? 	can I not be grassing?
can you not be grassing?
can he not be grassing?
can we not be grassing?
can you not be grassing?
can they not be grassing? 	can I not have grassed?
can you not have grassed?
can he not have grassed?
can we not have grassed?
can you not have grassed?
can they not have grassed? 	can I not have been grassing?
can you not have been grassing?
can he not have been grassing?
can we not have been grassing?
can you not have been grassing?
can they not have been grassing?