How to say hello in Persian
The first word almost every learner wants is hello, and in Persian it is warm, flexible, and easy to start with.
The everyday word for hello is salam سلام. It works at any time of day, with friends, family, shopkeepers, and strangers. If you learn one greeting first, learn this one.
More formal and respectful
To sound more respectful, you can say salam aleikom سلام علیکم, or offer a greeting with salam arz mikonam سلام عرض میکنم, which means "I offer my greetings." A more literary alternative is dorood درود.
Greetings by time of day
Sobh bekheyr صبح بخیر means good morning. Asr bekheyr عصر بخیر covers the afternoon and early evening, and shab bekheyr شب بخیر means good night, usually said when parting.
What comes after hello
Persian greetings rarely stop at one word. After salam, people ask how you are, so it helps to have chetori? (how are you, informal) ready. The greeting and the question travel together.
Start with salam, add a time-of-day greeting when it fits, and you already sound natural in most situations.