が燃えちゃう

… will burn up

→ が

phrase Uncommon #12,644

… will burn up A casual contraction of が燃えてしまう. It can suggest that something burns completely or that the burning is unwanted.

JA: 火を近づけると、紙が燃えちゃう。

EN: If you bring the fire close, the paper will burn up.