I may strengthen you may strengthen he may strengthen we may strengthen you may strengthen they may strengthen
V-ing form
I may be strengthening you may be strengthening he may be strengthening we may be strengthening you may be strengthening they may be strengthening
Perfect
I may have strengthened you may have strengthened he may have strengthened we may have strengthened you may have strengthened they may have strengthened
V-ing perfect
I may have been strengthening you may have been strengthening he may have been strengthening we may have been strengthening you may have been strengthening they may have been strengthening
Negation
Simple form
I may not strengthen you may not strengthen he may not strengthen we may not strengthen you may not strengthen they may not strengthen
V-ing form
I may not be strengthening you may not be strengthening he may not be strengthening we may not be strengthening you may not be strengthening they may not be strengthening
Perfect
I may not have strengthened you may not have strengthened he may not have strengthened we may not have strengthened you may not have strengthened they may not have strengthened
V-ing perfect
I may not have been strengthening you may not have been strengthening he may not have been strengthening we may not have been strengthening you may not have been strengthening they may not have been strengthening
Interrogative form
Simple form
may I strengthen? may you strengthen? may he strengthen? may we strengthen? may you strengthen? may they strengthen?
V-ing form
may I be strengthening? may you be strengthening? may he be strengthening? may we be strengthening? may you be strengthening? may they be strengthening?
Perfect
may I have strengthened? may you have strengthened? may he have strengthened? may we have strengthened? may you have strengthened? may they have strengthened?
V-ing perfect
may I have been strengthening? may you have been strengthening? may he have been strengthening? may we have been strengthening? may you have been strengthening? may they have been strengthening?
Interro-negative form
Simple form
may I not strengthen? may you not strengthen? may he not strengthen? may we not strengthen? may you not strengthen? may they not strengthen?
V-ing form
may I not be strengthening? may you not be strengthening? may he not be strengthening? may we not be strengthening? may you not be strengthening? may they not be strengthening?
Perfect
may I not have strengthened? may you not have strengthened? may he not have strengthened? may we not have strengthened? may you not have strengthened? may they not have strengthened?
V-ing perfect
may I not have been strengthening? may you not have been strengthening? may he not have been strengthening? may we not have been strengthening? may you not have been strengthening? may they not have been strengthening?