could endeavour
Regular verb: endeavour - endeavoured- endeavoured

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could endeavour
you could endeavour
she could endeavour
we could endeavour
you could endeavour
they could endeavour 	I could be endeavouring
you could be endeavouring
she could be endeavouring
we could be endeavouring
you could be endeavouring
they could be endeavouring	I could have endeavoured
you could have endeavoured
she could have endeavoured
we could have endeavoured
you could have endeavoured
they could have endeavoured	I could have been endeavouring
you could have been endeavouring
she could have been endeavouring
we could have been endeavouring
you could have been endeavouring
they could have been endeavouring	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't endeavour
you couldn't endeavour
she couldn't endeavour
we couldn't endeavour
you couldn't endeavour
they couldn't endeavour 	I couldn't be endeavouring
you couldn't be endeavouring
she couldn't be endeavouring
we couldn't be endeavouring
you couldn't be endeavouring
they couldn't be endeavouring	I couldn't have endeavoured
you couldn't have endeavoured
she couldn't have endeavoured
we couldn't have endeavoured
you couldn't have endeavoured
they couldn't have endeavoured	I couldn't have been endeavouring
you couldn't have been endeavouring
she couldn't have been endeavouring
we couldn't have been endeavouring
you couldn't have been endeavouring
they couldn't have been endeavouring	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I endeavour?
could you endeavour?
could she endeavour?
could we endeavour?
could you endeavour?
could they endeavour? 	could I be endeavouring?
could you be endeavouring?
could she be endeavouring?
could we be endeavouring?
could you be endeavouring?
could they be endeavouring? 	could I have endeavoured?
could you have endeavoured?
could she have endeavoured?
could we have endeavoured?
could you have endeavoured?
could they have endeavoured? 	could I have been endeavouring?
could you have been endeavouring?
could she have been endeavouring?
could we have been endeavouring?
could you have been endeavouring?
could they have been endeavouring? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I endeavour?
couldn't you endeavour?
couldn't she endeavour?
couldn't we endeavour?
couldn't you endeavour?
couldn't they endeavour? 	couldn't I be endeavouring?
couldn't you be endeavouring?
couldn't she be endeavouring?
couldn't we be endeavouring?
couldn't you be endeavouring?
couldn't they be endeavouring? 	couldn't I have endeavoured?
couldn't you have endeavoured?
couldn't she have endeavoured?
couldn't we have endeavoured?
couldn't you have endeavoured?
couldn't they have endeavoured? 	couldn't I have been endeavouring?
couldn't you have been endeavouring?
couldn't she have been endeavouring?
couldn't we have been endeavouring?
couldn't you have been endeavouring?
couldn't they have been endeavouring?