English verb conjugation
CAN UNDERSTAND

Irregular verb: understand - understood - understood

Affirmation

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

Negation

Simple form	V-ing form
I can't understand you can't understand he can't understand we can't understand you can't understand they can't understand	I can't be understanding you can't be understanding he can't be understanding we can't be understanding you can't be understanding they can't be understanding
Perfect	V-ing perfect
I can't have understood you can't have understood he can't have understood we can't have understood you can't have understood they can't have understood	I can't have been understanding you can't have been understanding he can't have been understanding we can't have been understanding you can't have been understanding they can't have been understanding

Interrogative form

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

Interro-negative form

Simple form	V-ing form
can't I understand? can't you understand? can't he understand? can't we understand? can't you understand? can't they understand?	can't I be understanding? can't you be understanding? can't he be understanding? can't we be understanding? can't you be understanding? can't they be understanding?
Perfect	V-ing perfect
can't I have understood? can't you have understood? can't he have understood? can't we have understood? can't you have understood? can't they have understood?	can't I have been understanding? can't you have been understanding? can't he have been understanding? can't we have been understanding? can't you have been understanding? can't they have been understanding?