English verb conjugation
COULD MAIL

Regular verb: mail - mailed - mailed

Affirmation

Simple form	V-ing form
I could mail you could mail she could mail we could mail you could mail they could mail	I could be mailing you could be mailing she could be mailing we could be mailing you could be mailing they could be mailing
Perfect	V-ing perfect
I could have mailed you could have mailed she could have mailed we could have mailed you could have mailed they could have mailed	I could have been mailing you could have been mailing she could have been mailing we could have been mailing you could have been mailing they could have been mailing

Negation

Simple form	V-ing form
I couldn't mail you couldn't mail she couldn't mail we couldn't mail you couldn't mail they couldn't mail	I couldn't be mailing you couldn't be mailing she couldn't be mailing we couldn't be mailing you couldn't be mailing they couldn't be mailing
Perfect	V-ing perfect
I couldn't have mailed you couldn't have mailed she couldn't have mailed we couldn't have mailed you couldn't have mailed they couldn't have mailed	I couldn't have been mailing you couldn't have been mailing she couldn't have been mailing we couldn't have been mailing you couldn't have been mailing they couldn't have been mailing

Interrogative form

Simple form	V-ing form
could I mail? could you mail? could she mail? could we mail? could you mail? could they mail?	could I be mailing? could you be mailing? could she be mailing? could we be mailing? could you be mailing? could they be mailing?
Perfect	V-ing perfect
could I have mailed? could you have mailed? could she have mailed? could we have mailed? could you have mailed? could they have mailed?	could I have been mailing? could you have been mailing? could she have been mailing? could we have been mailing? could you have been mailing? could they have been mailing?

Interro-negative form

Simple form	V-ing form
couldn't I mail? couldn't you mail? couldn't she mail? couldn't we mail? couldn't you mail? couldn't they mail?	couldn't I be mailing? couldn't you be mailing? couldn't she be mailing? couldn't we be mailing? couldn't you be mailing? couldn't they be mailing?
Perfect	V-ing perfect
couldn't I have mailed? couldn't you have mailed? couldn't she have mailed? couldn't we have mailed? couldn't you have mailed? couldn't they have mailed?	couldn't I have been mailing? couldn't you have been mailing? couldn't she have been mailing? couldn't we have been mailing? couldn't you have been mailing? couldn't they have been mailing?