English verb conjugation
CAN PRECERTIFY

Regular verb: precertify - precertified - precertified

Affirmation

Simple form	V-ing form
I can precertify you can precertify he can precertify we can precertify you can precertify they can precertify	I can be precertifying you can be precertifying he can be precertifying we can be precertifying you can be precertifying they can be precertifying
Perfect	V-ing perfect
I can have precertified you can have precertified he can have precertified we can have precertified you can have precertified they can have precertified	I can have been precertifying you can have been precertifying he can have been precertifying we can have been precertifying you can have been precertifying they can have been precertifying

Negation

Simple form	V-ing form
I can't precertify you can't precertify he can't precertify we can't precertify you can't precertify they can't precertify	I can't be precertifying you can't be precertifying he can't be precertifying we can't be precertifying you can't be precertifying they can't be precertifying
Perfect	V-ing perfect
I can't have precertified you can't have precertified he can't have precertified we can't have precertified you can't have precertified they can't have precertified	I can't have been precertifying you can't have been precertifying he can't have been precertifying we can't have been precertifying you can't have been precertifying they can't have been precertifying

Interrogative form

Simple form	V-ing form
can I precertify? can you precertify? can he precertify? can we precertify? can you precertify? can they precertify?	can I be precertifying? can you be precertifying? can he be precertifying? can we be precertifying? can you be precertifying? can they be precertifying?
Perfect	V-ing perfect
can I have precertified? can you have precertified? can he have precertified? can we have precertified? can you have precertified? can they have precertified?	can I have been precertifying? can you have been precertifying? can he have been precertifying? can we have been precertifying? can you have been precertifying? can they have been precertifying?

Interro-negative form

Simple form	V-ing form
can't I precertify? can't you precertify? can't he precertify? can't we precertify? can't you precertify? can't they precertify?	can't I be precertifying? can't you be precertifying? can't he be precertifying? can't we be precertifying? can't you be precertifying? can't they be precertifying?
Perfect	V-ing perfect
can't I have precertified? can't you have precertified? can't he have precertified? can't we have precertified? can't you have precertified? can't they have precertified?	can't I have been precertifying? can't you have been precertifying? can't he have been precertifying? can't we have been precertifying? can't you have been precertifying? can't they have been precertifying?