いらっしゃる (honorific replacement for いる・行く・来る)
いらっしゃいませ (imperative – greeting/welcome)
Note: Conjugates as a godan verb (ら行), but いらっしゃいます is the standard polite form (not いらっしゃります).
いらっしゃる is an honorific (尊敬語) verb that serves as the respectful equivalent of three common verbs: いる (to be/exist), いく行く (to go), and くる来る (to come). It is used when speaking about someone of higher status – such as a boss, teacher, customer, or elder – to show respect for their actions or presence.
Used to respectfully describe someone's presence or location.
Used to respectfully describe someone going somewhere.
Used to respectfully describe someone coming somewhere.
Although いらっしゃる ends in る, it conjugates as a godan (五段) verb with an irregular ます-form:
The form いらっしゃい is used as a casual greeting meaning "Welcome!" while いらっしゃいませ is the polite version heard in shops and restaurants.
Because いらっしゃる is 尊敬語 (respectful language), it is used to elevate the actions of others – never to describe yourself. Using it about yourself would be a significant social error. For humble speech about your own actions, use おる (humble form of いる) or まいる参る (humble form of 行く/来る) instead.