English verb conjugation
COULD RIDDLE

Regular verb: riddle - riddled - riddled

Affirmation

Simple form	V-ing form
I could riddle you could riddle he could riddle we could riddle you could riddle they could riddle	I could be riddling you could be riddling he could be riddling we could be riddling you could be riddling they could be riddling
Perfect	V-ing perfect
I could have riddled you could have riddled he could have riddled we could have riddled you could have riddled they could have riddled	I could have been riddling you could have been riddling he could have been riddling we could have been riddling you could have been riddling they could have been riddling

Negation

Simple form	V-ing form
I couldn't riddle you couldn't riddle he couldn't riddle we couldn't riddle you couldn't riddle they couldn't riddle	I couldn't be riddling you couldn't be riddling he couldn't be riddling we couldn't be riddling you couldn't be riddling they couldn't be riddling
Perfect	V-ing perfect
I couldn't have riddled you couldn't have riddled he couldn't have riddled we couldn't have riddled you couldn't have riddled they couldn't have riddled	I couldn't have been riddling you couldn't have been riddling he couldn't have been riddling we couldn't have been riddling you couldn't have been riddling they couldn't have been riddling

Interrogative form

Simple form	V-ing form
could I riddle? could you riddle? could he riddle? could we riddle? could you riddle? could they riddle?	could I be riddling? could you be riddling? could he be riddling? could we be riddling? could you be riddling? could they be riddling?
Perfect	V-ing perfect
could I have riddled? could you have riddled? could he have riddled? could we have riddled? could you have riddled? could they have riddled?	could I have been riddling? could you have been riddling? could he have been riddling? could we have been riddling? could you have been riddling? could they have been riddling?

Interro-negative form

Simple form	V-ing form
couldn't I riddle? couldn't you riddle? couldn't he riddle? couldn't we riddle? couldn't you riddle? couldn't they riddle?	couldn't I be riddling? couldn't you be riddling? couldn't he be riddling? couldn't we be riddling? couldn't you be riddling? couldn't they be riddling?
Perfect	V-ing perfect
couldn't I have riddled? couldn't you have riddled? couldn't he have riddled? couldn't we have riddled? couldn't you have riddled? couldn't they have riddled?	couldn't I have been riddling? couldn't you have been riddling? couldn't he have been riddling? couldn't we have been riddling? couldn't you have been riddling? couldn't they have been riddling?