may precess
Regular verb: precess - precessed- precessed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I may precess
you may precess
she may precess
we may precess
you may precess
they may precess 	I may be precessing
you may be precessing
she may be precessing
we may be precessing
you may be precessing
they may be precessing	I may have precessed
you may have precessed
she may have precessed
we may have precessed
you may have precessed
they may have precessed	I may have been precessing
you may have been precessing
she may have been precessing
we may have been precessing
you may have been precessing
they may have been precessing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mayn't precess
you mayn't precess
she mayn't precess
we mayn't precess
you mayn't precess
they mayn't precess 	I mayn't be precessing
you mayn't be precessing
she mayn't be precessing
we mayn't be precessing
you mayn't be precessing
they mayn't be precessing	I mayn't have precessed
you mayn't have precessed
she mayn't have precessed
we mayn't have precessed
you mayn't have precessed
they mayn't have precessed	I mayn't have been precessing
you mayn't have been precessing
she mayn't have been precessing
we mayn't have been precessing
you mayn't have been precessing
they mayn't have been precessing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
may I precess?
may you precess?
may she precess?
may we precess?
may you precess?
may they precess? 	may I be precessing?
may you be precessing?
may she be precessing?
may we be precessing?
may you be precessing?
may they be precessing? 	may I have precessed?
may you have precessed?
may she have precessed?
may we have precessed?
may you have precessed?
may they have precessed? 	may I have been precessing?
may you have been precessing?
may she have been precessing?
may we have been precessing?
may you have been precessing?
may they have been precessing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mayn't I precess?
mayn't you precess?
mayn't she precess?
mayn't we precess?
mayn't you precess?
mayn't they precess? 	mayn't I be precessing?
mayn't you be precessing?
mayn't she be precessing?
mayn't we be precessing?
mayn't you be precessing?
mayn't they be precessing? 	mayn't I have precessed?
mayn't you have precessed?
mayn't she have precessed?
mayn't we have precessed?
mayn't you have precessed?
mayn't they have precessed? 	mayn't I have been precessing?
mayn't you have been precessing?
mayn't she have been precessing?
mayn't we have been precessing?
mayn't you have been precessing?
mayn't they have been precessing?