I should fasten you should fasten she should fasten we should fasten you should fasten they should fasten
V-ing form
I should be fastening you should be fastening she should be fastening we should be fastening you should be fastening they should be fastening
Perfect
I should have fastened you should have fastened she should have fastened we should have fastened you should have fastened they should have fastened
V-ing perfect
I should have been fastening you should have been fastening she should have been fastening we should have been fastening you should have been fastening they should have been fastening
Negation
Simple form
I should not fasten you should not fasten she should not fasten we should not fasten you should not fasten they should not fasten
V-ing form
I should not be fastening you should not be fastening she should not be fastening we should not be fastening you should not be fastening they should not be fastening
Perfect
I should not have fastened you should not have fastened she should not have fastened we should not have fastened you should not have fastened they should not have fastened
V-ing perfect
I should not have been fastening you should not have been fastening she should not have been fastening we should not have been fastening you should not have been fastening they should not have been fastening
Interrogative form
Simple form
should I fasten? should you fasten? should she fasten? should we fasten? should you fasten? should they fasten?
V-ing form
should I be fastening? should you be fastening? should she be fastening? should we be fastening? should you be fastening? should they be fastening?
Perfect
should I have fastened? should you have fastened? should she have fastened? should we have fastened? should you have fastened? should they have fastened?
V-ing perfect
should I have been fastening? should you have been fastening? should she have been fastening? should we have been fastening? should you have been fastening? should they have been fastening?
Interro-negative form
Simple form
should I not fasten? should you not fasten? should she not fasten? should we not fasten? should you not fasten? should they not fasten?
V-ing form
should I not be fastening? should you not be fastening? should she not be fastening? should we not be fastening? should you not be fastening? should they not be fastening?
Perfect
should I not have fastened? should you not have fastened? should she not have fastened? should we not have fastened? should you not have fastened? should they not have fastened?
V-ing perfect
should I not have been fastening? should you not have been fastening? should she not have been fastening? should we not have been fastening? should you not have been fastening? should they not have been fastening?