English verb conjugation
COULD TIP

Regular verb: tip - tipped - tipped

Affirmation

Simple form	V-ing form
I could tip you could tip she could tip we could tip you could tip they could tip	I could be tipping you could be tipping she 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 she 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 she 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 she 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 she 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 she 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 she 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 she tip? could we tip? could you tip? could they tip?	could I be tipping? could you be tipping? could she 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 she 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 she 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 she 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 she 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 she 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 she not have been tipping? could we not have been tipping? could you not have been tipping? could they not have been tipping?