can attest
Regular verb: attest - attested- attested

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can attest
you can attest
she can attest
we can attest
you can attest
they can attest 	I can be attesting
you can be attesting
she can be attesting
we can be attesting
you can be attesting
they can be attesting	I can have attested
you can have attested
she 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
she 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 can't attest
you can't attest
she can't attest
we can't attest
you can't attest
they can't attest 	I can't be attesting
you can't be attesting
she can't be attesting
we can't be attesting
you can't be attesting
they can't be attesting	I can't have attested
you can't have attested
she can't have attested
we can't have attested
you can't have attested
they can't have attested	I can't have been attesting
you can't have been attesting
she can't have been attesting
we can't have been attesting
you can't have been attesting
they can't have been attesting	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I attest?
can you attest?
can she attest?
can we attest?
can you attest?
can they attest? 	can I be attesting?
can you be attesting?
can she be attesting?
can we be attesting?
can you be attesting?
can they be attesting? 	can I have attested?
can you have attested?
can she 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 she 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't I attest?
can't you attest?
can't she attest?
can't we attest?
can't you attest?
can't they attest? 	can't I be attesting?
can't you be attesting?
can't she be attesting?
can't we be attesting?
can't you be attesting?
can't they be attesting? 	can't I have attested?
can't you have attested?
can't she have attested?
can't we have attested?
can't you have attested?
can't they have attested? 	can't I have been attesting?
can't you have been attesting?
can't she have been attesting?
can't we have been attesting?
can't you have been attesting?
can't they have been attesting?