could gravitate
Regular verb: gravitate - gravitated- gravitated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could gravitate
you could gravitate
he could gravitate
we could gravitate
you could gravitate
they could gravitate 	I could be gravitating
you could be gravitating
he could be gravitating
we could be gravitating
you could be gravitating
they could be gravitating	I could have gravitated
you could have gravitated
he could have gravitated
we could have gravitated
you could have gravitated
they could have gravitated	I could have been gravitating
you could have been gravitating
he could have been gravitating
we could have been gravitating
you could have been gravitating
they could have been gravitating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't gravitate
you couldn't gravitate
he couldn't gravitate
we couldn't gravitate
you couldn't gravitate
they couldn't gravitate 	I couldn't be gravitating
you couldn't be gravitating
he couldn't be gravitating
we couldn't be gravitating
you couldn't be gravitating
they couldn't be gravitating	I couldn't have gravitated
you couldn't have gravitated
he couldn't have gravitated
we couldn't have gravitated
you couldn't have gravitated
they couldn't have gravitated	I couldn't have been gravitating
you couldn't have been gravitating
he couldn't have been gravitating
we couldn't have been gravitating
you couldn't have been gravitating
they couldn't have been gravitating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I gravitate?
could you gravitate?
could he gravitate?
could we gravitate?
could you gravitate?
could they gravitate? 	could I be gravitating?
could you be gravitating?
could he be gravitating?
could we be gravitating?
could you be gravitating?
could they be gravitating? 	could I have gravitated?
could you have gravitated?
could he have gravitated?
could we have gravitated?
could you have gravitated?
could they have gravitated? 	could I have been gravitating?
could you have been gravitating?
could he have been gravitating?
could we have been gravitating?
could you have been gravitating?
could they have been gravitating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I gravitate?
couldn't you gravitate?
couldn't he gravitate?
couldn't we gravitate?
couldn't you gravitate?
couldn't they gravitate? 	couldn't I be gravitating?
couldn't you be gravitating?
couldn't he be gravitating?
couldn't we be gravitating?
couldn't you be gravitating?
couldn't they be gravitating? 	couldn't I have gravitated?
couldn't you have gravitated?
couldn't he have gravitated?
couldn't we have gravitated?
couldn't you have gravitated?
couldn't they have gravitated? 	couldn't I have been gravitating?
couldn't you have been gravitating?
couldn't he have been gravitating?
couldn't we have been gravitating?
couldn't you have been gravitating?
couldn't they have been gravitating?