日本語
--de irassharu
to be (polite sentence ending in its honorific form)
[--de irassharu]…is a respectful (honorific expression) equivalent of "--desu".
こちらは たなかさんで いらっしゃいます。
This is Mr./Ms. Tanaka.
--desu
〜です
to be (polite sentence ending)
いたす
to do (humble form)
いらっしゃい
Welcome (said to someone who is visiting)
いらっしゃる
to come (honorific form)
to be (honorific form)
to go (honorific form)