could thud
Regular verb: thud - thudded- thudded

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could thud
you could thud
she could thud
we could thud
you could thud
they could thud 	I could be thudding
you could be thudding
she could be thudding
we could be thudding
you could be thudding
they could be thudding	I could have thudded
you could have thudded
she could have thudded
we could have thudded
you could have thudded
they could have thudded	I could have been thudding
you could have been thudding
she could have been thudding
we could have been thudding
you could have been thudding
they could have been thudding	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't thud
you couldn't thud
she couldn't thud
we couldn't thud
you couldn't thud
they couldn't thud 	I couldn't be thudding
you couldn't be thudding
she couldn't be thudding
we couldn't be thudding
you couldn't be thudding
they couldn't be thudding	I couldn't have thudded
you couldn't have thudded
she couldn't have thudded
we couldn't have thudded
you couldn't have thudded
they couldn't have thudded	I couldn't have been thudding
you couldn't have been thudding
she couldn't have been thudding
we couldn't have been thudding
you couldn't have been thudding
they couldn't have been thudding	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I thud?
could you thud?
could she thud?
could we thud?
could you thud?
could they thud? 	could I be thudding?
could you be thudding?
could she be thudding?
could we be thudding?
could you be thudding?
could they be thudding? 	could I have thudded?
could you have thudded?
could she have thudded?
could we have thudded?
could you have thudded?
could they have thudded? 	could I have been thudding?
could you have been thudding?
could she have been thudding?
could we have been thudding?
could you have been thudding?
could they have been thudding? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I thud?
couldn't you thud?
couldn't she thud?
couldn't we thud?
couldn't you thud?
couldn't they thud? 	couldn't I be thudding?
couldn't you be thudding?
couldn't she be thudding?
couldn't we be thudding?
couldn't you be thudding?
couldn't they be thudding? 	couldn't I have thudded?
couldn't you have thudded?
couldn't she have thudded?
couldn't we have thudded?
couldn't you have thudded?
couldn't they have thudded? 	couldn't I have been thudding?
couldn't you have been thudding?
couldn't she have been thudding?
couldn't we have been thudding?
couldn't you have been thudding?
couldn't they have been thudding?