我跟你一起去。

Put the person you are following right after 跟. If you want to go with Mom, say 我跟妈妈一起去. The structure is very logical. You don't need to change the verb for tense. Just say it as it is. It works for walking to the store or flying across the world. It’s like a verbal glue that sticks you to your friend’s plans.

Use it when a friend mentions they are going to get bubble tea. Use it when your colleague is heading to a boring meeting. It shows support and companionship. It’s perfect for those 'me too' moments. If someone looks lonely heading out, this phrase is a hero. It’s also great for safety when walking home at night.

Don't use it if you aren't actually invited to a private event. If your boss is going to a performance review, maybe stay put. Avoid it if the other person clearly needs space. It can sound a bit clingy if used every single time someone leaves the room. Don't use it for 'coming' to the speaker's location; use 来 (lái) instead of 去.

Chinese culture highly values 'togetherness' or 热闹 (rènao). Doing things alone can sometimes be seen as lonely. Offering to go along is a sign of a good relationship. It shows you value their company more than the destination. In the past, traveling together was also a matter of safety and shared resources. Today, it’s just the ultimate 'bestie' move.

You can shorten it to 我也去 (I’m going too). Or make it a question: 我跟你一起去，好吗？ (I go with you, okay?). If you want to be extra cute, add a 吧 at the end. 我们一起去吧！ makes it a group suggestion. For a very casual vibe, just say 同去 (going together) in some regions. But the full version is always the safest bet.