У моей сестры красивые кудри.

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Breakdown of У моей сестры красивые кудри.

• красивый: beautiful
• сестра: the sister
• кудря: the curl

Questions & Answers about У моей сестры красивые кудри.

Why does Russian use у моей сестры instead of something that directly means my sister has?

Russian usually expresses possession with the pattern у + genitive + possessed thing.

So:

• У моей сестры красивые кудри.
• literally: At my sister [there are] beautiful curls
• natural English: My sister has beautiful curls.

Russian does have the verb иметь (to have), but for ordinary possession it is often less natural and can sound formal or bookish. So у моей сестры... is the normal everyday way to say it.

Why is it моей сестры, not моя сестра?

Because the preposition у requires the genitive case.

The base form is:

• моя сестра = my sister

After у, both words change to genitive:

• моя → моей
• сестра → сестры

So:

• у моей сестры = at my sister / my sister has

What case is красивые кудри in?