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 couldn't drain
you couldn't drain
he couldn't drain
we couldn't drain
you couldn't drain
they couldn't drain 	I couldn't be draining
you couldn't be draining
he couldn't be draining
we couldn't be draining
you couldn't be draining
they couldn't be draining	I couldn't have drained
you couldn't have drained
he couldn't have drained
we couldn't have drained
you couldn't have drained
they couldn't have drained	I couldn't have been draining
you couldn't have been draining
he couldn't have been draining
we couldn't have been draining
you couldn't have been draining
they couldn't 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 	
couldn't I drain?
couldn't you drain?
couldn't he drain?
couldn't we drain?
couldn't you drain?
couldn't they drain? 	couldn't I be draining?
couldn't you be draining?
couldn't he be draining?
couldn't we be draining?
couldn't you be draining?
couldn't they be draining? 	couldn't I have drained?
couldn't you have drained?
couldn't he have drained?
couldn't we have drained?
couldn't you have drained?
couldn't they have drained? 	couldn't I have been draining?
couldn't you have been draining?
couldn't he have been draining?
couldn't we have been draining?
couldn't you have been draining?
couldn't they have been draining?