いらっしゃるTo be (Honorific), To come (Honorific), To go (Honorific)

がいる combines the particle が with the verb いる to express the existence of living or animate beings, like people or animals. いらっしゃる is the honorific equivalent of いる, as well as 行く and 来る. In other words, がいらっしゃる is the honorific version of がいる, and いらっしゃいますか is the honorific equivalent of いますか, 行きますか, or 来ますか.

These are honorific forms used to respectfully describe others' actions. お～になる is used with regular verbs, e.g. 書く 'write' becoming お書きになる (same meaning, but showing respect to the writer). いらっしゃる is a special honorific form that replaces 行く, 来る, and いる, for which the お～になる form is not used.

Both いらっしゃる and くる express movement toward the speaker, similar to the English 'come.' The key difference is politeness: くる is the neutral verb used in everyday contexts, while いらっしゃる is an honorific verb used to show respect for someone's movement. Note that いらっしゃる also serves as the honorific form of いる, いく, and くる.

Both いらっしゃる and いく express movement away from the speaker, similar to the English 'go.' The key difference is politeness: いく is a neutral verb used in everyday contexts, while いらっしゃる is a polite, honorific verb used to show respect for someone's movement. Note that いらっしゃる also serves as the honorific form of いる, くる, and いく.