could drain
Regular verb: drain - drained- drained

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could drain
you could drain
he could drain
we could drain
you could drain
they could drain 	I could be draining
you could be draining
he could be draining
we could be draining
you could be draining
they could be draining	I could have drained
you could have drained
he could have drained
we could have drained
you could have drained
they could have drained	I could have been draining
you could have been draining
he could have been draining
we could have been draining
you could have been draining
they could have been draining	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not drain
you could not drain
he could not drain
we could not drain
you could not drain
they could not drain 	I could not be draining
you could not be draining
he could not be draining
we could not be draining
you could not be draining
they could not be draining	I could not have drained
you could not have drained
he could not have drained
we could not have drained
you could not have drained
they could not have drained	I could not have been draining
you could not have been draining
he could not have been draining
we could not have been draining
you could not have been draining
they could not have been draining	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I drain?
could you drain?
could he drain?
could we drain?
could you drain?
could they drain? 	could I be draining?
could you be draining?
could he be draining?
could we be draining?
could you be draining?
could they be draining? 	could I have drained?
could you have drained?
could he have drained?
could we have drained?
could you have drained?
could they have drained? 	could I have been draining?
could you have been draining?
could he have been draining?
could we have been draining?
could you have been draining?
could they have been draining? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not drain?
could you not drain?
could he not drain?
could we not drain?
could you not drain?
could they not drain? 	could I not be draining?
could you not be draining?
could he not be draining?
could we not be draining?
could you not be draining?
could they not be draining? 	could I not have drained?
could you not have drained?
could he not have drained?
could we not have drained?
could you not have drained?
could they not have drained? 	could I not have been draining?
could you not have been draining?
could he not have been draining?
could we not have been draining?
could you not have been draining?
could they not have been draining?