一起去吧。

You can use this phrase as a standalone sentence. Or, you can add a destination at the end. For example, 我们一起去超市吧 means "Let's go to the supermarket together." It works perfectly when you see someone leaving. If they are heading to lunch, you can jump in. It shows you want to share an experience. It is very versatile for any group size. Even if it is just you and one friend, it works.

Use it when you want to be inclusive. It is great for the office when heading to a meeting. Use it with friends when a new movie comes out. It is perfect for texting when making weekend plans. If you see a colleague grabbing coffee, say it! It helps build rapport quickly. It is also a polite way to accept an invitation. If someone says they are going somewhere, you can ask to join this way.

Do not use it in extremely formal ceremonies. It is a bit too casual for a royal wedding or a funeral. Avoid using it if you are actually trying to be alone. If you say it, people will likely follow you! Don't use it with a high-ranking boss unless you have a close relationship. It might seem a bit too bold or presumptuous. Also, don't use it if the destination is private, like a doctor's appointment.

Chinese culture places a huge emphasis on 'collectivism.' Doing things alone can sometimes look a bit lonely or 'sad' in a traditional sense. By saying 一起去吧, you are reinforcing the bond of the group. It is very common for friends to wait for each other just to walk to class together. Sharing the journey is often more important than the destination itself. It reflects the value of 'Ren' or human-to-human connection.

You can swap 去 (go) for other verbs. Try 一起吃吧 (Let's eat together). Or 一起玩吧 (Let's hang out/play together). If you want to be more casual, you can just say 走吧 (Let's go). To make it a question, you can say 我们要不要一起去? (Shall we go together?). Adding 我们 (we) at the start makes it feel even more like a team effort.