could scan
Regular verb: scan - scanned- scanned

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could scan
you could scan
she could scan
we could scan
you could scan
they could scan 	I could be scanning
you could be scanning
she could be scanning
we could be scanning
you could be scanning
they could be scanning	I could have scanned
you could have scanned
she could have scanned
we could have scanned
you could have scanned
they could have scanned	I could have been scanning
you could have been scanning
she could have been scanning
we could have been scanning
you could have been scanning
they could have been scanning	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't scan
you couldn't scan
she couldn't scan
we couldn't scan
you couldn't scan
they couldn't scan 	I couldn't be scanning
you couldn't be scanning
she couldn't be scanning
we couldn't be scanning
you couldn't be scanning
they couldn't be scanning	I couldn't have scanned
you couldn't have scanned
she couldn't have scanned
we couldn't have scanned
you couldn't have scanned
they couldn't have scanned	I couldn't have been scanning
you couldn't have been scanning
she couldn't have been scanning
we couldn't have been scanning
you couldn't have been scanning
they couldn't have been scanning	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I scan?
could you scan?
could she scan?
could we scan?
could you scan?
could they scan? 	could I be scanning?
could you be scanning?
could she be scanning?
could we be scanning?
could you be scanning?
could they be scanning? 	could I have scanned?
could you have scanned?
could she have scanned?
could we have scanned?
could you have scanned?
could they have scanned? 	could I have been scanning?
could you have been scanning?
could she have been scanning?
could we have been scanning?
could you have been scanning?
could they have been scanning? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I scan?
couldn't you scan?
couldn't she scan?
couldn't we scan?
couldn't you scan?
couldn't they scan? 	couldn't I be scanning?
couldn't you be scanning?
couldn't she be scanning?
couldn't we be scanning?
couldn't you be scanning?
couldn't they be scanning? 	couldn't I have scanned?
couldn't you have scanned?
couldn't she have scanned?
couldn't we have scanned?
couldn't you have scanned?
couldn't they have scanned? 	couldn't I have been scanning?
couldn't you have been scanning?
couldn't she have been scanning?
couldn't we have been scanning?
couldn't you have been scanning?
couldn't they have been scanning?