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