English verb conjugation
COULD TIP

Regular verb: tip - tipped - tipped

Affirmation

Simple form	V-ing form
I could tip you could tip he could tip we could tip you could tip they could tip	I could be tipping you could be tipping he could be tipping we could be tipping you could be tipping they could be tipping
Perfect	V-ing perfect
I could have tipped you could have tipped he could have tipped we could have tipped you could have tipped they could have tipped	I could have been tipping you could have been tipping he could have been tipping we could have been tipping you could have been tipping they could have been tipping

Negation

Simple form	V-ing form
I could not tip you could not tip he could not tip we could not tip you could not tip they could not tip	I could not be tipping you could not be tipping he could not be tipping we could not be tipping you could not be tipping they could not be tipping
Perfect	V-ing perfect
I could not have tipped you could not have tipped he could not have tipped we could not have tipped you could not have tipped they could not have tipped	I could not have been tipping you could not have been tipping he could not have been tipping we could not have been tipping you could not have been tipping they could not have been tipping

Interrogative form

Simple form	V-ing form
could I tip? could you tip? could he tip? could we tip? could you tip? could they tip?	could I be tipping? could you be tipping? could he be tipping? could we be tipping? could you be tipping? could they be tipping?
Perfect	V-ing perfect
could I have tipped? could you have tipped? could he have tipped? could we have tipped? could you have tipped? could they have tipped?	could I have been tipping? could you have been tipping? could he have been tipping? could we have been tipping? could you have been tipping? could they have been tipping?

Interro-negative form

Simple form	V-ing form
could I not tip? could you not tip? could he not tip? could we not tip? could you not tip? could they not tip?	could I not be tipping? could you not be tipping? could he not be tipping? could we not be tipping? could you not be tipping? could they not be tipping?
Perfect	V-ing perfect
could I not have tipped? could you not have tipped? could he not have tipped? could we not have tipped? could you not have tipped? could they not have tipped?	could I not have been tipping? could you not have been tipping? could he not have been tipping? could we not have been tipping? could you not have been tipping? could they not have been tipping?