Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I could read read you could read read he could read read we could read read you could read read they could read read
V-ing form
I could be read reading you could be read reading he could be read reading we could be read reading you could be read reading they could be read reading
Perfect
I could have read readed you could have read readed he could have read readed we could have read readed you could have read readed they could have read readed
V-ing perfect
I could have been read reading you could have been read reading he could have been read reading we could have been read reading you could have been read reading they could have been read reading
Negation
Simple form
I couldn't read read you couldn't read read he couldn't read read we couldn't read read you couldn't read read they couldn't read read
V-ing form
I couldn't be read reading you couldn't be read reading he couldn't be read reading we couldn't be read reading you couldn't be read reading they couldn't be read reading
Perfect
I couldn't have read readed you couldn't have read readed he couldn't have read readed we couldn't have read readed you couldn't have read readed they couldn't have read readed
V-ing perfect
I couldn't have been read reading you couldn't have been read reading he couldn't have been read reading we couldn't have been read reading you couldn't have been read reading they couldn't have been read reading
Interrogative form
Simple form
could I read read? could you read read? could he read read? could we read read? could you read read? could they read read?
V-ing form
could I be read reading? could you be read reading? could he be read reading? could we be read reading? could you be read reading? could they be read reading?
Perfect
could I have read readed? could you have read readed? could he have read readed? could we have read readed? could you have read readed? could they have read readed?
V-ing perfect
could I have been read reading? could you have been read reading? could he have been read reading? could we have been read reading? could you have been read reading? could they have been read reading?
Interro-negative form
Simple form
couldn't I read read? couldn't you read read? couldn't he read read? couldn't we read read? couldn't you read read? couldn't they read read?
V-ing form
couldn't I be read reading? couldn't you be read reading? couldn't he be read reading? couldn't we be read reading? couldn't you be read reading? couldn't they be read reading?
Perfect
couldn't I have read readed? couldn't you have read readed? couldn't he have read readed? couldn't we have read readed? couldn't you have read readed? couldn't they have read readed?
V-ing perfect
couldn't I have been read reading? couldn't you have been read reading? couldn't he have been read reading? couldn't we have been read reading? couldn't you have been read reading? couldn't they have been read reading?