English verb conjugation
COULD HUM

Regular verb: hum - humed - humed

Affirmation

Simple form	V-ing form
I could hum you could hum he could hum we could hum you could hum they could hum	I could be huming you could be huming he could be huming we could be huming you could be huming they could be huming
Perfect	V-ing perfect
I could have humed you could have humed he could have humed we could have humed you could have humed they could have humed	I could have been huming you could have been huming he could have been huming we could have been huming you could have been huming they could have been huming

Negation

Simple form	V-ing form
I could not hum you could not hum he could not hum we could not hum you could not hum they could not hum	I could not be huming you could not be huming he could not be huming we could not be huming you could not be huming they could not be huming
Perfect	V-ing perfect
I could not have humed you could not have humed he could not have humed we could not have humed you could not have humed they could not have humed	I could not have been huming you could not have been huming he could not have been huming we could not have been huming you could not have been huming they could not have been huming

Interrogative form

Simple form	V-ing form
could I hum? could you hum? could he hum? could we hum? could you hum? could they hum?	could I be huming? could you be huming? could he be huming? could we be huming? could you be huming? could they be huming?
Perfect	V-ing perfect
could I have humed? could you have humed? could he have humed? could we have humed? could you have humed? could they have humed?	could I have been huming? could you have been huming? could he have been huming? could we have been huming? could you have been huming? could they have been huming?

Interro-negative form

Simple form	V-ing form
could I not hum? could you not hum? could he not hum? could we not hum? could you not hum? could they not hum?	could I not be huming? could you not be huming? could he not be huming? could we not be huming? could you not be huming? could they not be huming?
Perfect	V-ing perfect
could I not have humed? could you not have humed? could he not have humed? could we not have humed? could you not have humed? could they not have humed?	could I not have been huming? could you not have been huming? could he not have been huming? could we not have been huming? could you not have been huming? could they not have been huming?