English verb conjugation
COULD PREBOIL

Regular verb: preboil - preboiled - preboiled

Affirmation

Simple form	V-ing form
I could preboil you could preboil he could preboil we could preboil you could preboil they could preboil	I could be preboiling you could be preboiling he could be preboiling we could be preboiling you could be preboiling they could be preboiling
Perfect	V-ing perfect
I could have preboiled you could have preboiled he could have preboiled we could have preboiled you could have preboiled they could have preboiled	I could have been preboiling you could have been preboiling he could have been preboiling we could have been preboiling you could have been preboiling they could have been preboiling

Negation

Simple form	V-ing form
I could not preboil you could not preboil he could not preboil we could not preboil you could not preboil they could not preboil	I could not be preboiling you could not be preboiling he could not be preboiling we could not be preboiling you could not be preboiling they could not be preboiling
Perfect	V-ing perfect
I could not have preboiled you could not have preboiled he could not have preboiled we could not have preboiled you could not have preboiled they could not have preboiled	I could not have been preboiling you could not have been preboiling he could not have been preboiling we could not have been preboiling you could not have been preboiling they could not have been preboiling

Interrogative form

Simple form	V-ing form
could I preboil? could you preboil? could he preboil? could we preboil? could you preboil? could they preboil?	could I be preboiling? could you be preboiling? could he be preboiling? could we be preboiling? could you be preboiling? could they be preboiling?
Perfect	V-ing perfect
could I have preboiled? could you have preboiled? could he have preboiled? could we have preboiled? could you have preboiled? could they have preboiled?	could I have been preboiling? could you have been preboiling? could he have been preboiling? could we have been preboiling? could you have been preboiling? could they have been preboiling?

Interro-negative form

Simple form	V-ing form
could I not preboil? could you not preboil? could he not preboil? could we not preboil? could you not preboil? could they not preboil?	could I not be preboiling? could you not be preboiling? could he not be preboiling? could we not be preboiling? could you not be preboiling? could they not be preboiling?
Perfect	V-ing perfect
could I not have preboiled? could you not have preboiled? could he not have preboiled? could we not have preboiled? could you not have preboiled? could they not have preboiled?	could I not have been preboiling? could you not have been preboiling? could he not have been preboiling? could we not have been preboiling? could you not have been preboiling? could they not have been preboiling?