What is the difference between the imperative forms of the -aru verbs?


What is the difference between these imperative forms:

nas- **ai**

nas- **are**

nas- **aimase**

nas- **aimashi**

(As far as I understand these verb forms apply only to the honorific –aru
verbs _irassharu, ossharu, kudasaru, gozaru_ and _nasaru_ , or am I mistaken?)




nasai and nasaimase are イ音便 forms for nasare and nasarimase. nasaimashi is an
uncommon alternative for nasaimase. nasai and nasaimase are different in that
mase is more formal (for a customer perhaps) and might give a kind of refined
air to it in some cases.

