English verb conjugation
COULD SAILPLANE

Regular verb: sailplane - sailplaned - sailplaned

Affirmation

Simple form	V-ing form
I could sailplane you could sailplane she could sailplane we could sailplane you could sailplane they could sailplane	I could be sailplaning you could be sailplaning she could be sailplaning we could be sailplaning you could be sailplaning they could be sailplaning
Perfect	V-ing perfect
I could have sailplaned you could have sailplaned she could have sailplaned we could have sailplaned you could have sailplaned they could have sailplaned	I could have been sailplaning you could have been sailplaning she could have been sailplaning we could have been sailplaning you could have been sailplaning they could have been sailplaning

Negation

Simple form	V-ing form
I couldn't sailplane you couldn't sailplane she couldn't sailplane we couldn't sailplane you couldn't sailplane they couldn't sailplane	I couldn't be sailplaning you couldn't be sailplaning she couldn't be sailplaning we couldn't be sailplaning you couldn't be sailplaning they couldn't be sailplaning
Perfect	V-ing perfect
I couldn't have sailplaned you couldn't have sailplaned she couldn't have sailplaned we couldn't have sailplaned you couldn't have sailplaned they couldn't have sailplaned	I couldn't have been sailplaning you couldn't have been sailplaning she couldn't have been sailplaning we couldn't have been sailplaning you couldn't have been sailplaning they couldn't have been sailplaning

Interrogative form

Simple form	V-ing form
could I sailplane? could you sailplane? could she sailplane? could we sailplane? could you sailplane? could they sailplane?	could I be sailplaning? could you be sailplaning? could she be sailplaning? could we be sailplaning? could you be sailplaning? could they be sailplaning?
Perfect	V-ing perfect
could I have sailplaned? could you have sailplaned? could she have sailplaned? could we have sailplaned? could you have sailplaned? could they have sailplaned?	could I have been sailplaning? could you have been sailplaning? could she have been sailplaning? could we have been sailplaning? could you have been sailplaning? could they have been sailplaning?

Interro-negative form

Simple form	V-ing form
couldn't I sailplane? couldn't you sailplane? couldn't she sailplane? couldn't we sailplane? couldn't you sailplane? couldn't they sailplane?	couldn't I be sailplaning? couldn't you be sailplaning? couldn't she be sailplaning? couldn't we be sailplaning? couldn't you be sailplaning? couldn't they be sailplaning?
Perfect	V-ing perfect
couldn't I have sailplaned? couldn't you have sailplaned? couldn't she have sailplaned? couldn't we have sailplaned? couldn't you have sailplaned? couldn't they have sailplaned?	couldn't I have been sailplaning? couldn't you have been sailplaning? couldn't she have been sailplaning? couldn't we have been sailplaning? couldn't you have been sailplaning? couldn't they have been sailplaning?