Learn Turkish: Siz balık alın, et almayın. - You, buy fish; do not buy meat.

In Turkish, the verb usually goes at the very end. Here, we have two mini-sentences joined together by a comma. The subject for both is Siz (You), which sits at the very beginning. Then comes the object (balık or et), and finally the verb (alın or almayın) to finish out each clause.

Why don't the objects balık (fish) and et (meat) have any suffixes on them?

Because they are general, non-specific objects. You are saying "buy fish" (any fish), not "buy the fish". In Turkish, you only add a special object suffix (the accusative case) when you are talking about a specific, defined thing. General objects stay in their bare dictionary form and are placed right before the verb.

Why is the verb alın instead of just al?

Since the sentence starts with Siz (You, plural or formal), the verb needs to match it. To give a command to a group of people, or to be polite/formal to one person, we add the suffix -ın (or -in, -un, -ün) to the verb root. So, the root al (buy/take) becomes alın.

How is the negative command almayın formed?