Usages of zài
她 现在 在 学习 呢。tā xiànzài zài xuéxí ne.
She is studying now.
他 在 做 这 个 吗？tā zài zuò zhè gè ma?
Is he doing this?
你 在 做 什么？nǐ zài zuò shénme?
What are you doing?
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