English verb conjugation
COULD THUD

Regular verb: thud - thudded - thudded

Affirmation

Simple form	V-ing form
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
Perfect	V-ing perfect
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
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
Perfect	V-ing perfect
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
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?
Perfect	V-ing perfect
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
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?
Perfect	V-ing perfect
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?