Learn German: Ich sehe heute den Chef. - I am seeing the boss today.

In this sentence, Chef is the direct object (the person receiving the action of being seen), which means it must be in the accusative case. For masculine nouns like Chef, the word for "the" changes from der to den in the accusative.

Why is heute placed before den Chef? Can I say "Ich sehe den Chef heute"?

In German, words that tell you when something happens (like heute) usually come right after the verb and before the object. While people would understand you if you put it at the end, putting heute early in the sentence sounds much more natural to a German speaker.

The translation says "I am seeing," but isn't there a separate "-ing" verb form in German?

No, German doesn't have a present continuous ("-ing") tense. The simple present tense ich sehe translates to both "I see" and "I am seeing." You just rely on context or time words like heute to show that an action is happening right now or around this time.

Does Chef mean "head cook" like it does in English?

No, Chef is a classic false friend! In German, der Chef means "the boss" or "the manager." If you want to talk about a chef in a restaurant, you would use the word der Koch.