هناك خطر!

Using it is very simple. You just place it after the subject you are talking about. If you want to say 'He is in danger,' you say هو في خطر. If you want to say 'The cat is in danger,' you say القطة في خطر. It does not change based on gender or number. This makes it a very friendly phrase for your brain to remember.

Use it when you see something risky. Maybe your friend is driving too fast. Maybe you see a child playing near a busy street. It is also great for dramatic flair. If you forgot your wife's birthday, you might tell your friend, أنا في خطر! (I am in danger!). It works for serious emergencies and for life's little disasters.

Do not use this for minor inconveniences. If you ran out of milk, you are not في خطر. That is just annoying. Also, avoid using it in very high-level academic writing unless you are discussing specific safety data. It is a bit too direct for a formal research paper. Keep it for real-life action.

In Arabic culture, expressing concern for others is a big deal. People often use this phrase to show they care. If someone says a child is في خطر, neighbors will likely rush to help. It is a phrase that triggers a protective instinct. It is deeply rooted in the communal nature of Middle Eastern societies.

If the danger is very big, you can add كبير (big) to make it في خطر كبير. In some dialects, people might say في ورطة (in a fix/mess). But في خطر is understood from Morocco to Iraq. It is the gold standard for warning others.