
Regular verb: seem - seemed - seemed
| Simple form | V-ing form | 
| - - it may seem - - - | - - it may be seeming - - - | 
| Perfect | V-ing perfect | 
| - - it may have seemed - - - | - - it may have been seeming - - - | 
| Simple form | V-ing form | 
| - - it may not seem - - - | - - it may not be seeming - - - | 
| Perfect | V-ing perfect | 
| - - it may not have seemed - - - | - - it may not have been seeming - - - | 
| Simple form | V-ing form | 
| - - may it seem? - - - | - - may it be seeming? - - - | 
| Perfect | V-ing perfect | 
| - - may it have seemed? - - - | - - may it have been seeming? - - - | 
| Simple form | V-ing form | 
| - - may it not seem? - - - | - - may it not be seeming? - - - | 
| Perfect | V-ing perfect | 
| - - may it not have seemed? - - - | - - may it not have been seeming? - - - |