英语你在干嘛怎么说呢

在英文中，可以用以下句子来询问某人正在做什么：

"What are you doing?"
"What's going on?"
"What's up?"
"What's happening?"

例如：

"Hey, what are you doing?"
"Hi, what's going on?"
"Hey there, what's up?"
"Hello, what's happening?"

这些问句都可以用来询问别人正在做什么。