〜はもちろん

About

The ～はもちろん pattern is a combination of the は particle and the adverb 「もちろん」 ("of course; certainly").

The ～XはもちろんY pattern is used to express "not only X (obvious thing), but also Y".

E.g. 平日へいじつはもちろん、土日どにちも遅おそくまで働はたらくことがある。 "Not only do I work late on weekdays, but there are times when I work late on Saturday and Sunday as well."

E.g. 東京とうきょうは、家賃やちんが高たかいのはもちろん、物価ぶっかも高たかい。 "As for Tokyo, of course, the rent is high, but the prices of things are also high."

E.g. マイクは、イタリア語ごはもちろん、日本語にほんごも上手じょうずだ。 "Mike is good at Italian, of course, but he's also good at Japanese."

Compared to the similar grammar point ～だけでなく, ～はもちろん should be preceded by a factor that is obvious to the listener/reader.

Summary

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  ～XはもちろんY is used to express "not only X (obvious thing), but also Y"

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  ～はもちろん should be preceded by a factor that is obvious to the listener/reader