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