What is the difference between おはようございます and おはよう?
おはようございます is formal — use it with teachers, bosses, seniors, and in professional contexts. おはよう is casual — fine with friends, family, and close colleagues. The ございます suffix elevates the politeness to the same level as です/ます speech.
When should I use こんにちは vs こんばんは?
Use こんにちは from around 10–11 AM until dusk (~5–6 PM depending on season). Switch to こんばんは once it is dark outside. Neither has a strictly formal or casual alternative — both work across registers.
What does お疲れ様です mean?
It means "you must be tired / good work." It is the standard workplace greeting between colleagues — said when passing someone in the hall, finishing a task together, or leaving for the day. With close friends it shortens to おつかれ.
Can I write こんにちわ?
こんにちわ is an informal spelling seen on social media, but standard Japanese always uses こんにちは. The は is a particle that is pronounced wa. For JLPT or any formal writing, always use こんにちは.
What should I say when someone leaves the house?
The person leaving says いってきます (I'll go and come back). The person at home responds いってらっしゃい (please go safely and return). The same exchange applies in offices when a coworker steps out.
What is よろしくお願いします used for?
It covers "nice to meet you," "please take care of this," and "I look forward to working with you." Say it when first meeting someone professionally, after making a request, or to close a formal email. The even more formal version is よろしくお願いいたします.