Having hunger, thirst and fear in German
When talking about how you feel physically or emotionally, English usually pairs the verb "to be" with an adjective. You might say you are hungry, thirsty, or afraid. German takes a different approach. Instead of being these things, you literally have them. You use the verb haben followed by a noun like Hunger or Angst.
English speakers also tend to trip over minor illnesses. While you have "a" cold in English, you simply have cold in German, dropping the article entirely.
For basic physical needs, German almost always uses haben with nouns. If you want a snack, you have Hunger or Appetit. If you need a drink, you have Durst.
The same pattern applies to emotional states. Instead of being afraid, you have fear. You can use Angst or the slightly more formal Furcht. If you are experiencing anxiety, you also have Angst. When you feel pressured, you have Stress.
You will also see this verb choice in common everyday expressions, such as having luck (Glück haben) or feeling like doing something (Lust haben).
When you are sick in English, you usually use an indefinite article. You have a fever, a cough, or a cold. In German, you drop the article and use the noun by itself. You simply have Fieber, Husten, or Schnupfen.
This rule also applies to various aches. German has specific nouns for these, combining the body part with either Schmerzen or Weh. If your head hurts, you have Kopfweh. For your throat, you have Halsschmerzen or Halsweh. If your teeth hurt, you have Zahnschmerzen or Zahnweh. None of these take an article.
Because words like Hunger and Angst are nouns, you cannot describe them with adverbs like you would in English. In English, you are "very" hungry. In German, you cannot say "sehr Hunger". Instead, you must use adjectives. You usually have big hunger (großen Hunger) or a lot of fear (viel Angst).
Whenever you want to express a basic bodily state, a feeling, or a minor illness in German, stop and think before using the verb "to be". In most cases, you will sound much more natural by using haben combined with a noun without an article.