could navigate
Regular verb: navigate - navigated- navigated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could navigate
you could navigate
she could navigate
we could navigate
you could navigate
they could navigate 	I could be navigating
you could be navigating
she could be navigating
we could be navigating
you could be navigating
they could be navigating	I could have navigated
you could have navigated
she could have navigated
we could have navigated
you could have navigated
they could have navigated	I could have been navigating
you could have been navigating
she could have been navigating
we could have been navigating
you could have been navigating
they could have been navigating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't navigate
you couldn't navigate
she couldn't navigate
we couldn't navigate
you couldn't navigate
they couldn't navigate 	I couldn't be navigating
you couldn't be navigating
she couldn't be navigating
we couldn't be navigating
you couldn't be navigating
they couldn't be navigating	I couldn't have navigated
you couldn't have navigated
she couldn't have navigated
we couldn't have navigated
you couldn't have navigated
they couldn't have navigated	I couldn't have been navigating
you couldn't have been navigating
she couldn't have been navigating
we couldn't have been navigating
you couldn't have been navigating
they couldn't have been navigating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I navigate?
could you navigate?
could she navigate?
could we navigate?
could you navigate?
could they navigate? 	could I be navigating?
could you be navigating?
could she be navigating?
could we be navigating?
could you be navigating?
could they be navigating? 	could I have navigated?
could you have navigated?
could she have navigated?
could we have navigated?
could you have navigated?
could they have navigated? 	could I have been navigating?
could you have been navigating?
could she have been navigating?
could we have been navigating?
could you have been navigating?
could they have been navigating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I navigate?
couldn't you navigate?
couldn't she navigate?
couldn't we navigate?
couldn't you navigate?
couldn't they navigate? 	couldn't I be navigating?
couldn't you be navigating?
couldn't she be navigating?
couldn't we be navigating?
couldn't you be navigating?
couldn't they be navigating? 	couldn't I have navigated?
couldn't you have navigated?
couldn't she have navigated?
couldn't we have navigated?
couldn't you have navigated?
couldn't they have navigated? 	couldn't I have been navigating?
couldn't you have been navigating?
couldn't she have been navigating?
couldn't we have been navigating?
couldn't you have been navigating?
couldn't they have been navigating?