I may lengthen you may lengthen he may lengthen we may lengthen you may lengthen they may lengthen
V-ing form
I may be lengthening you may be lengthening he may be lengthening we may be lengthening you may be lengthening they may be lengthening
Perfect
I may have lengthened you may have lengthened he may have lengthened we may have lengthened you may have lengthened they may have lengthened
V-ing perfect
I may have been lengthening you may have been lengthening he may have been lengthening we may have been lengthening you may have been lengthening they may have been lengthening
Negation
Simple form
I mayn't lengthen you mayn't lengthen he mayn't lengthen we mayn't lengthen you mayn't lengthen they mayn't lengthen
V-ing form
I mayn't be lengthening you mayn't be lengthening he mayn't be lengthening we mayn't be lengthening you mayn't be lengthening they mayn't be lengthening
Perfect
I mayn't have lengthened you mayn't have lengthened he mayn't have lengthened we mayn't have lengthened you mayn't have lengthened they mayn't have lengthened
V-ing perfect
I mayn't have been lengthening you mayn't have been lengthening he mayn't have been lengthening we mayn't have been lengthening you mayn't have been lengthening they mayn't have been lengthening
Interrogative form
Simple form
may I lengthen? may you lengthen? may he lengthen? may we lengthen? may you lengthen? may they lengthen?
V-ing form
may I be lengthening? may you be lengthening? may he be lengthening? may we be lengthening? may you be lengthening? may they be lengthening?
Perfect
may I have lengthened? may you have lengthened? may he have lengthened? may we have lengthened? may you have lengthened? may they have lengthened?
V-ing perfect
may I have been lengthening? may you have been lengthening? may he have been lengthening? may we have been lengthening? may you have been lengthening? may they have been lengthening?
Interro-negative form
Simple form
mayn't I lengthen? mayn't you lengthen? mayn't he lengthen? mayn't we lengthen? mayn't you lengthen? mayn't they lengthen?
V-ing form
mayn't I be lengthening? mayn't you be lengthening? mayn't he be lengthening? mayn't we be lengthening? mayn't you be lengthening? mayn't they be lengthening?
Perfect
mayn't I have lengthened? mayn't you have lengthened? mayn't he have lengthened? mayn't we have lengthened? mayn't you have lengthened? mayn't they have lengthened?
V-ing perfect
mayn't I have been lengthening? mayn't you have been lengthening? mayn't he have been lengthening? mayn't we have been lengthening? mayn't you have been lengthening? mayn't they have been lengthening?