can preboil
Regular verb: preboil - preboiled- preboiled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can preboil
you can preboil
she can preboil
we can preboil
you can preboil
they can preboil 	I can be preboiling
you can be preboiling
she can be preboiling
we can be preboiling
you can be preboiling
they can be preboiling	I can have preboiled
you can have preboiled
she can have preboiled
we can have preboiled
you can have preboiled
they can have preboiled	I can have been preboiling
you can have been preboiling
she can have been preboiling
we can have been preboiling
you can have been preboiling
they can have been preboiling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I cannot preboil
you cannot preboil
she cannot preboil
we cannot preboil
you cannot preboil
they cannot preboil 	I cannot be preboiling
you cannot be preboiling
she cannot be preboiling
we cannot be preboiling
you cannot be preboiling
they cannot be preboiling	I cannot have preboiled
you cannot have preboiled
she cannot have preboiled
we cannot have preboiled
you cannot have preboiled
they cannot have preboiled	I cannot have been preboiling
you cannot have been preboiling
she cannot have been preboiling
we cannot have been preboiling
you cannot have been preboiling
they cannot have been preboiling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I preboil?
can you preboil?
can she preboil?
can we preboil?
can you preboil?
can they preboil? 	can I be preboiling?
can you be preboiling?
can she be preboiling?
can we be preboiling?
can you be preboiling?
can they be preboiling? 	can I have preboiled?
can you have preboiled?
can she have preboiled?
can we have preboiled?
can you have preboiled?
can they have preboiled? 	can I have been preboiling?
can you have been preboiling?
can she have been preboiling?
can we have been preboiling?
can you have been preboiling?
can they have been preboiling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I not preboil?
can you not preboil?
can she not preboil?
can we not preboil?
can you not preboil?
can they not preboil? 	can I not be preboiling?
can you not be preboiling?
can she not be preboiling?
can we not be preboiling?
can you not be preboiling?
can they not be preboiling? 	can I not have preboiled?
can you not have preboiled?
can she not have preboiled?
can we not have preboiled?
can you not have preboiled?
can they not have preboiled? 	can I not have been preboiling?
can you not have been preboiling?
can she not have been preboiling?
can we not have been preboiling?
can you not have been preboiling?
can they not have been preboiling?