Thank you for sharing Chinese lessons.

May I ask a question on "past tense" in Chinese? I see from

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* 你怎么了？不舒服吗？

nĭ zěnme le? bù shūfu ma?

หนี เจิ่นเมอ เลอ? ปู้ ซู ฝุ มา?

คุณเป็นอะไรรึเปล่า ไม่สบายหรอ

What happened to you? Were you sick?

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The Thai translation is in the present tense, but the English translation is in the past tense.

My question is: How do we indicate the past tense in Chinese?