Breakdown of tā chī le yào yǐhòu, wǎnshang zhōngyú tuìshāo le.
Used after a verb. Marks that an action is completed.
Used at the end of a sentence. Marks a change of state or new situation.
Questions & Answers about tā chī le yào yǐhòu, wǎnshang zhōngyú tuìshāo le.
They do different jobs.
The first 了 in 吃了药 marks the action of taking the medicine as completed.
The second 了 at the end of the sentence, in 退烧了, marks a new situation or change of state: before, she had a fever; now, the fever has gone down.
So:
- 吃了药 = she took the medicine
- 退烧了 = she has gotten better / the fever has gone down now
This is a very common pattern in Mandarin.
In Mandarin, 吃药 is the normal way to say take medicine, especially for medicine you swallow, such as pills or liquid medicine.
Chinese often uses 吃 much more broadly than English uses eat. It can cover consuming something orally, not just food.
Some related expressions are:
- 吃药 = take medicine
- 喝药 = drink medicine, especially liquid medicine
- 打针 = get an injection
- 擦药 = apply medicine
So even though 吃 literally means eat, 吃药 is completely natural.