This pattern is a polite way to invite someone to do something or to suggest an activity. It is formed by taking the ます-stem of a verb (the part before ます) and adding ませんか. It means "would you like to...?" or "shall we...?" and is very common in everyday conversation.

Use it when you want to ask someone if they want to do something with you, such as going to a movie or eating together. It is more polite than just saying 〜ましょう (let's) because it gives the other person a choice to decline. The response can be positive (はい、いいですね) or negative (ちょっと...).

Because it is a question, it is usually spoken with a rising intonation. It is appropriate in both casual and formal situations, but especially useful when you want to be polite and not presumptuous.