could guarantee
Regular verb: guarantee - guaranteed- guaranteed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could guarantee
you could guarantee
she could guarantee
we could guarantee
you could guarantee
they could guarantee 	I could be guaranteeing
you could be guaranteeing
she could be guaranteeing
we could be guaranteeing
you could be guaranteeing
they could be guaranteeing	I could have guaranteed
you could have guaranteed
she could have guaranteed
we could have guaranteed
you could have guaranteed
they could have guaranteed	I could have been guaranteeing
you could have been guaranteeing
she could have been guaranteeing
we could have been guaranteeing
you could have been guaranteeing
they could have been guaranteeing	

Negation 	
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I could not guarantee
you could not guarantee
she could not guarantee
we could not guarantee
you could not guarantee
they could not guarantee 	I could not be guaranteeing
you could not be guaranteeing
she could not be guaranteeing
we could not be guaranteeing
you could not be guaranteeing
they could not be guaranteeing	I could not have guaranteed
you could not have guaranteed
she could not have guaranteed
we could not have guaranteed
you could not have guaranteed
they could not have guaranteed	I could not have been guaranteeing
you could not have been guaranteeing
she could not have been guaranteeing
we could not have been guaranteeing
you could not have been guaranteeing
they could not have been guaranteeing	

Interrogative form 	
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could I guarantee?
could you guarantee?
could she guarantee?
could we guarantee?
could you guarantee?
could they guarantee? 	could I be guaranteeing?
could you be guaranteeing?
could she be guaranteeing?
could we be guaranteeing?
could you be guaranteeing?
could they be guaranteeing? 	could I have guaranteed?
could you have guaranteed?
could she have guaranteed?
could we have guaranteed?
could you have guaranteed?
could they have guaranteed? 	could I have been guaranteeing?
could you have been guaranteeing?
could she have been guaranteeing?
could we have been guaranteeing?
could you have been guaranteeing?
could they have been guaranteeing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not guarantee?
could you not guarantee?
could she not guarantee?
could we not guarantee?
could you not guarantee?
could they not guarantee? 	could I not be guaranteeing?
could you not be guaranteeing?
could she not be guaranteeing?
could we not be guaranteeing?
could you not be guaranteeing?
could they not be guaranteeing? 	could I not have guaranteed?
could you not have guaranteed?
could she not have guaranteed?
could we not have guaranteed?
could you not have guaranteed?
could they not have guaranteed? 	could I not have been guaranteeing?
could you not have been guaranteeing?
could she not have been guaranteeing?
could we not have been guaranteeing?
could you not have been guaranteeing?
could they not have been guaranteeing?