Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I could think think you could think think she could think think we could think think you could think think they could think think
V-ing form
I could be think thinking you could be think thinking she could be think thinking we could be think thinking you could be think thinking they could be think thinking
Perfect
I could have think thinked you could have think thinked she could have think thinked we could have think thinked you could have think thinked they could have think thinked
V-ing perfect
I could have been think thinking you could have been think thinking she could have been think thinking we could have been think thinking you could have been think thinking they could have been think thinking
Negation
Simple form
I could not think think you could not think think she could not think think we could not think think you could not think think they could not think think
V-ing form
I could not be think thinking you could not be think thinking she could not be think thinking we could not be think thinking you could not be think thinking they could not be think thinking
Perfect
I could not have think thinked you could not have think thinked she could not have think thinked we could not have think thinked you could not have think thinked they could not have think thinked
V-ing perfect
I could not have been think thinking you could not have been think thinking she could not have been think thinking we could not have been think thinking you could not have been think thinking they could not have been think thinking
Interrogative form
Simple form
could I think think? could you think think? could she think think? could we think think? could you think think? could they think think?
V-ing form
could I be think thinking? could you be think thinking? could she be think thinking? could we be think thinking? could you be think thinking? could they be think thinking?
Perfect
could I have think thinked? could you have think thinked? could she have think thinked? could we have think thinked? could you have think thinked? could they have think thinked?
V-ing perfect
could I have been think thinking? could you have been think thinking? could she have been think thinking? could we have been think thinking? could you have been think thinking? could they have been think thinking?
Interro-negative form
Simple form
could I not think think? could you not think think? could she not think think? could we not think think? could you not think think? could they not think think?
V-ing form
could I not be think thinking? could you not be think thinking? could she not be think thinking? could we not be think thinking? could you not be think thinking? could they not be think thinking?
Perfect
could I not have think thinked? could you not have think thinked? could she not have think thinked? could we not have think thinked? could you not have think thinked? could they not have think thinked?
V-ing perfect
could I not have been think thinking? could you not have been think thinking? could she not have been think thinking? could we not have been think thinking? could you not have been think thinking? could they not have been think thinking?