こんにちは

Using it is simple but feels like a dance. You say こんにちは while giving a small, respectful nod. You do not need a full 90-degree bow here. Just a slight tilt of the head will do. Keep your voice clear and friendly. If you are entering a shop, say it toward the staff. If you are meeting a friend's parent, say it with a smile. It is the 'Goldilocks' of greetings—not too stiff, not too loose.

Timing is everything in Japan. Start using こんにちは around 10:30 AM or 11:00 AM. Use it all through the afternoon while the sun is up. It works at the grocery store or the library. It is perfect when passing a neighbor on the street. Use it when joining a Zoom call with Japanese colleagues. It even works when you are texting a group of classmates for the first time.

Do not use it first thing in the morning. That is for おはよう. Also, put it away once the sun sets. At that point, switch to こんばんは. Curiously, you rarely say it to your own family at home. Saying it to your mom in the kitchen might make her think you are joking. It is also a bit too 'distant' for your absolute best friends. With them, a simple 'Yo!' or 'Osu!' is more common.

This phrase has a secret history. Long ago, people said full sentences like 'As for today, how are you feeling?' Over centuries, the 'how are you feeling' part just fell off. We were left with the topic marker は. This is why we write it with the character for 'ha' but pronounce it 'wa.' It is a linguistic fossil of a much longer, very polite conversation. It shows how Japanese culture values the start of a connection.

In very casual settings, you might hear こんちは. It is just a faster, lazier version. Young men sometimes grunt ちわーす which is a super-compressed slang version. In very formal business settings, you might stick to the standard version but add a deeper bow. If you are writing it, always use Hiragana. Using Kanji for this phrase is very rare and looks like you are writing a historical novel.