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"何" is pronounced as "なん" before counter-words like in "何時{なんじ}", "何歳{なんさい}" etc; or before particles like in "何で", "何とか" etc.

However, it remains to be pronounced as "なに" in some words like "何事{なにごと}", "何色{なにいろ}", "何者{なにもの}" etc. It can also be pronounced both ways like in "何か".

What is the logic/origin behind this pronunciation difference?

Lukman
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2 Answers2

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This isn't a complete answer, but there is a strong tendency to shorten to なん when 何 is followed by a 'n', 'd' or 't' sound.

This obviously doesn't address your first two examples, however.

jkerian
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Usually we use "なん" in the following cases :

  • when the first syllabe of the next word is part of the lines "-た", "-だ" and "-な",
  • as mentioned by Luckman, when we ask a question about a number like in "何時{なんじ}" and "何分{なんぷん}".

In any others cases, we use "なに".

Hubert M.
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  • Hey can I ask an additional question? I've seen 「何になる」 been read as 「なんになる」. Does なに become なん before a particle? – JulioJ Jan 28 '19 at 13:17