watashi wa tomodachi no denwabangou o machigaemashita.

I got my friend's phone number wrong.

Breakdown of watashi wa tomodachi no denwabangou o machigaemashita.

• は: topic particle
• 私わたし: I
• を: direct object particle
• 友とも達だち: friend

Questions & Answers about watashi wa tomodachi no denwabangou o machigaemashita.

Why is は used after 私?

は marks 私 as the topic of the sentence: as for me or speaking of me.

So 私は does not simply mean I in a one-to-one way. It means something more like:

• As for me, ...
• I, ...

This is very common in Japanese. The topic is what the sentence is about, and then the rest of the sentence says something about that topic.

In this sentence:

• 私 = I
• は = topic marker

So 私は友達の電話番号を間違えました means As for me, I got my friend’s phone number wrong.

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Can 私 be omitted?

Yes. Very often, Japanese omits subjects and topics when they are already clear from context.

So in a natural conversation, people might just say:

• 友達の電話番号を間違えました。

This can still mean I got my friend’s phone number wrong, if it is obvious that the speaker is talking about themself.

Japanese often leaves out information that English normally states directly.

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What does の do in 友達の電話番号?

の connects nouns. Here it shows a relationship between 友達 and .