Learn Turkish: Kadife şal ve şapka karıştı. - The velvet shawl and the hat got mixed up.

In Turkish, when the subject is inanimate (like objects, concepts, or animals) and plural or made of multiple items, the verb must stay in the third-person singular form. That is why we use karıştı instead of karıştılar.

Kadife is a noun meaning velvet. Why isn't there a compound suffix on şal, like kadife şalı?

When you use a noun to describe the material an object is made of, it acts directly as an adjective. You do not use a compound noun structure. Therefore, it is simply kadife şal (velvet shawl), just like altın yüzük (gold ring) or tahta masa (wooden table).

Doesn't the verb karışmak usually mean to interfere or to meddle?

It depends on the context! When used with people or situations (often taking a dative object), it means to interfere or get involved. However, when talking about physical objects, roads, or liquids, it means to get mixed up, confused, or blended.

Does kadife apply to both the shawl and the hat here?

Grammatically, it can be slightly ambiguous, exactly like in English. It could mean both items are velvet, or just the shawl. Native speakers rely on context to know for sure, though it usually just applies to the first noun unless they form a very tight pair.