は何をするつもりなの

what are you planning to do?

→ は
phrase Rare #40,294
what are you planning to do? An informal question about someone's plans or intentions. The topic marker は precedes the phrase, and the sentence-ending の adds a questioning tone.
JA: トムは何をするつもりなの?
EN: What is Tom planning to do?

トムは何をするつもりなの

What is Tom planning to do?

は何をするつもりなの

What are you planning to do?

引退したは何をするつもりなの

What do you plan to do after you retire?

夏休み期間は何をするつもりなの

What are you planning to do during summer vacation?