English verb conjugation
COULD UNDERSTAND

Irregular verb: understand - understood - understood

Affirmation

Simple form	V-ing form
I could understand you could understand he could understand we could understand you could understand they could understand	I could be understanding you could be understanding he could be understanding we could be understanding you could be understanding they could be understanding
Perfect	V-ing perfect
I could have understood you could have understood he could have understood we could have understood you could have understood they could have understood	I could have been understanding you could have been understanding he could have been understanding we could have been understanding you could have been understanding they could have been understanding

Negation

Simple form	V-ing form
I could not understand you could not understand he could not understand we could not understand you could not understand they could not understand	I could not be understanding you could not be understanding he could not be understanding we could not be understanding you could not be understanding they could not be understanding
Perfect	V-ing perfect
I could not have understood you could not have understood he could not have understood we could not have understood you could not have understood they could not have understood	I could not have been understanding you could not have been understanding he could not have been understanding we could not have been understanding you could not have been understanding they could not have been understanding

Interrogative form

Simple form	V-ing form
could I understand? could you understand? could he understand? could we understand? could you understand? could they understand?	could I be understanding? could you be understanding? could he be understanding? could we be understanding? could you be understanding? could they be understanding?
Perfect	V-ing perfect
could I have understood? could you have understood? could he have understood? could we have understood? could you have understood? could they have understood?	could I have been understanding? could you have been understanding? could he have been understanding? could we have been understanding? could you have been understanding? could they have been understanding?

Interro-negative form

Simple form	V-ing form
could I not understand? could you not understand? could he not understand? could we not understand? could you not understand? could they not understand?	could I not be understanding? could you not be understanding? could he not be understanding? could we not be understanding? could you not be understanding? could they not be understanding?
Perfect	V-ing perfect
could I not have understood? could you not have understood? could he not have understood? could we not have understood? could you not have understood? could they not have understood?	could I not have been understanding? could you not have been understanding? could he not have been understanding? could we not have been understanding? could you not have been understanding? could they not have been understanding?