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 couldn't preboil you couldn't preboil he couldn't preboil we couldn't preboil you couldn't preboil they couldn't preboil	I couldn't be preboiling you couldn't be preboiling he couldn't be preboiling we couldn't be preboiling you couldn't be preboiling they couldn't be preboiling
Perfect	V-ing perfect
I couldn't have preboiled you couldn't have preboiled he couldn't have preboiled we couldn't have preboiled you couldn't have preboiled they couldn't have preboiled	I couldn't have been preboiling you couldn't have been preboiling he couldn't have been preboiling we couldn't have been preboiling you couldn't have been preboiling they couldn't 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
couldn't I preboil? couldn't you preboil? couldn't he preboil? couldn't we preboil? couldn't you preboil? couldn't they preboil?	couldn't I be preboiling? couldn't you be preboiling? couldn't he be preboiling? couldn't we be preboiling? couldn't you be preboiling? couldn't they be preboiling?
Perfect	V-ing perfect
couldn't I have preboiled? couldn't you have preboiled? couldn't he have preboiled? couldn't we have preboiled? couldn't you have preboiled? couldn't they have preboiled?	couldn't I have been preboiling? couldn't you have been preboiling? couldn't he have been preboiling? couldn't we have been preboiling? couldn't you have been preboiling? couldn't they have been preboiling?