I may cost you may cost she may cost we may cost you may cost they may cost
V-ing form
I may be costing you may be costing she may be costing we may be costing you may be costing they may be costing
Perfect
I may have cost you may have cost she may have cost we may have cost you may have cost they may have cost
V-ing perfect
I may have been costing you may have been costing she may have been costing we may have been costing you may have been costing they may have been costing
Negation
Simple form
I mayn't cost you mayn't cost she mayn't cost we mayn't cost you mayn't cost they mayn't cost
V-ing form
I mayn't be costing you mayn't be costing she mayn't be costing we mayn't be costing you mayn't be costing they mayn't be costing
Perfect
I mayn't have cost you mayn't have cost she mayn't have cost we mayn't have cost you mayn't have cost they mayn't have cost
V-ing perfect
I mayn't have been costing you mayn't have been costing she mayn't have been costing we mayn't have been costing you mayn't have been costing they mayn't have been costing
Interrogative form
Simple form
may I cost? may you cost? may she cost? may we cost? may you cost? may they cost?
V-ing form
may I be costing? may you be costing? may she be costing? may we be costing? may you be costing? may they be costing?
Perfect
may I have cost? may you have cost? may she have cost? may we have cost? may you have cost? may they have cost?
V-ing perfect
may I have been costing? may you have been costing? may she have been costing? may we have been costing? may you have been costing? may they have been costing?
Interro-negative form
Simple form
mayn't I cost? mayn't you cost? mayn't she cost? mayn't we cost? mayn't you cost? mayn't they cost?
V-ing form
mayn't I be costing? mayn't you be costing? mayn't she be costing? mayn't we be costing? mayn't you be costing? mayn't they be costing?
Perfect
mayn't I have cost? mayn't you have cost? mayn't she have cost? mayn't we have cost? mayn't you have cost? mayn't they have cost?
V-ing perfect
mayn't I have been costing? mayn't you have been costing? mayn't she have been costing? mayn't we have been costing? mayn't you have been costing? mayn't they have been costing?