Yes, your sentence is correct. “Why are you forever jumping on me for such unimportant things?” means “Why are you always criticizing me for small things?” You can also use “get on my case” with the same meaning. That would sound like: “Why are you always getting on my case about such unimportant things?” Both are natural. Jump on me is a little stronger and more emotional; get on my case is very common in everyday English.

Hello! Great examples — you’re using “jump on me” correctly ✅. 📌 Jump on (someone) = criticize, attack verbally, or react angrily. “Why are you always jumping on me for being late?” 📌 Get on my case = very similar meaning, but it’s more informal and American in style. “Stop getting on my case about homework!” So yes — you can say: “Why are you forever jumping on me for such unimportant things?” (slightly stronger, feels like a sudden attack) “Why are you always getting on my case about unimportant things?” (more casual, everyday speech). 👉 Quick tip: “Jump on me” = feels more intense. “Get on my case” = feels more conversational. ⚡ Homework: Try writing 2–3 sentences where you swap one phrase for the other and see how the feeling changes.

"get(ting) on my case" sounds fine, an alternative would be "bothering me". "jump on me" sounds a little wierd.