could rosin
Regular verb: rosin - rosined- rosined

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could rosin
you could rosin
he could rosin
we could rosin
you could rosin
they could rosin 	I could be rosining
you could be rosining
he could be rosining
we could be rosining
you could be rosining
they could be rosining	I could have rosined
you could have rosined
he could have rosined
we could have rosined
you could have rosined
they could have rosined	I could have been rosining
you could have been rosining
he could have been rosining
we could have been rosining
you could have been rosining
they could have been rosining	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not rosin
you could not rosin
he could not rosin
we could not rosin
you could not rosin
they could not rosin 	I could not be rosining
you could not be rosining
he could not be rosining
we could not be rosining
you could not be rosining
they could not be rosining	I could not have rosined
you could not have rosined
he could not have rosined
we could not have rosined
you could not have rosined
they could not have rosined	I could not have been rosining
you could not have been rosining
he could not have been rosining
we could not have been rosining
you could not have been rosining
they could not have been rosining	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I rosin?
could you rosin?
could he rosin?
could we rosin?
could you rosin?
could they rosin? 	could I be rosining?
could you be rosining?
could he be rosining?
could we be rosining?
could you be rosining?
could they be rosining? 	could I have rosined?
could you have rosined?
could he have rosined?
could we have rosined?
could you have rosined?
could they have rosined? 	could I have been rosining?
could you have been rosining?
could he have been rosining?
could we have been rosining?
could you have been rosining?
could they have been rosining? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not rosin?
could you not rosin?
could he not rosin?
could we not rosin?
could you not rosin?
could they not rosin? 	could I not be rosining?
could you not be rosining?
could he not be rosining?
could we not be rosining?
could you not be rosining?
could they not be rosining? 	could I not have rosined?
could you not have rosined?
could he not have rosined?
could we not have rosined?
could you not have rosined?
could they not have rosined? 	could I not have been rosining?
could you not have been rosining?
could he not have been rosining?
could we not have been rosining?
could you not have been rosining?
could they not have been rosining?