can attest
Regular verb: attest - attested- attested

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can attest
you can attest
he can attest
we can attest
you can attest
they can attest 	I can be attesting
you can be attesting
he can be attesting
we can be attesting
you can be attesting
they can be attesting	I can have attested
you can have attested
he can have attested
we can have attested
you can have attested
they can have attested	I can have been attesting
you can have been attesting
he can have been attesting
we can have been attesting
you can have been attesting
they can have been attesting	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I cannot attest
you cannot attest
he cannot attest
we cannot attest
you cannot attest
they cannot attest 	I cannot be attesting
you cannot be attesting
he cannot be attesting
we cannot be attesting
you cannot be attesting
they cannot be attesting	I cannot have attested
you cannot have attested
he cannot have attested
we cannot have attested
you cannot have attested
they cannot have attested	I cannot have been attesting
you cannot have been attesting
he cannot have been attesting
we cannot have been attesting
you cannot have been attesting
they cannot have been attesting	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I attest?
can you attest?
can he attest?
can we attest?
can you attest?
can they attest? 	can I be attesting?
can you be attesting?
can he be attesting?
can we be attesting?
can you be attesting?
can they be attesting? 	can I have attested?
can you have attested?
can he have attested?
can we have attested?
can you have attested?
can they have attested? 	can I have been attesting?
can you have been attesting?
can he have been attesting?
can we have been attesting?
can you have been attesting?
can they have been attesting? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I not attest?
can you not attest?
can he not attest?
can we not attest?
can you not attest?
can they not attest? 	can I not be attesting?
can you not be attesting?
can he not be attesting?
can we not be attesting?
can you not be attesting?
can they not be attesting? 	can I not have attested?
can you not have attested?
can he not have attested?
can we not have attested?
can you not have attested?
can they not have attested? 	can I not have been attesting?
can you not have been attesting?
can he not have been attesting?
can we not have been attesting?
can you not have been attesting?
can they not have been attesting?