مشغول شوية

You can use it as a standalone answer. Or, you can drop it into a longer sentence. If you are male, say mashghul. If you are female, say mashghula. The word shwayya stays the same for everyone. It is very flexible and grammatically simple for beginners.

Use it when a friend calls while you are working. Use it when a waiter asks if you want dessert. It works perfectly in office settings too. It shows you are productive but still polite. It is great for texting when you can't chat long. Use it to set boundaries with your time.

Don't use it during a massive emergency. It sounds too casual for a life-or-death situation. Avoid it if you are talking to your boss about a deadline. In that case, you might need a more formal excuse. Don't use it if you are actually free. People might think you are avoiding them specifically. It's a 'soft' excuse, not a 'hard' no.

In many Arabic-speaking countries, hospitality is a huge deal. Saying 'no' to an invitation can feel like a rejection. By adding shwayya (a little), you save face for everyone. It implies that under different circumstances, you would love to talk. It reflects the cultural value of politeness over bluntness. It's the 'polite white lie' of the Middle East.

You might hear mashghul katheer if someone is very busy. In Egypt, you might hear mashghul habba. In the Gulf, some say mashghul tikkah. However, shwayya is understood everywhere from Morocco to Iraq. It is the most universal way to express a minor time crunch.