English verb conjugation
COULD PROBE

Regular verb: probe - probed - probed

Affirmation

Simple form	V-ing form
I could probe you could probe he could probe we could probe you could probe they could probe	I could be probing you could be probing he could be probing we could be probing you could be probing they could be probing
Perfect	V-ing perfect
I could have probed you could have probed he could have probed we could have probed you could have probed they could have probed	I could have been probing you could have been probing he could have been probing we could have been probing you could have been probing they could have been probing

Negation

Simple form	V-ing form
I couldn't probe you couldn't probe he couldn't probe we couldn't probe you couldn't probe they couldn't probe	I couldn't be probing you couldn't be probing he couldn't be probing we couldn't be probing you couldn't be probing they couldn't be probing
Perfect	V-ing perfect
I couldn't have probed you couldn't have probed he couldn't have probed we couldn't have probed you couldn't have probed they couldn't have probed	I couldn't have been probing you couldn't have been probing he couldn't have been probing we couldn't have been probing you couldn't have been probing they couldn't have been probing

Interrogative form

Simple form	V-ing form
could I probe? could you probe? could he probe? could we probe? could you probe? could they probe?	could I be probing? could you be probing? could he be probing? could we be probing? could you be probing? could they be probing?
Perfect	V-ing perfect
could I have probed? could you have probed? could he have probed? could we have probed? could you have probed? could they have probed?	could I have been probing? could you have been probing? could he have been probing? could we have been probing? could you have been probing? could they have been probing?

Interro-negative form

Simple form	V-ing form
couldn't I probe? couldn't you probe? couldn't he probe? couldn't we probe? couldn't you probe? couldn't they probe?	couldn't I be probing? couldn't you be probing? couldn't he be probing? couldn't we be probing? couldn't you be probing? couldn't they be probing?
Perfect	V-ing perfect
couldn't I have probed? couldn't you have probed? couldn't he have probed? couldn't we have probed? couldn't you have probed? couldn't they have probed?	couldn't I have been probing? couldn't you have been probing? couldn't he have been probing? couldn't we have been probing? couldn't you have been probing? couldn't they have been probing?