Copula
n. 系词, 介体, 接合部\\n[医] 介体; (舌)联桁; 交配
✅ 同义词
📖 牛津释义
copula
n
(grammar) type of verb that connects a subject with its complement 系词（即连系动词, 用以连结主语及其补语）
In `George became ill', the verb `became' is a copula. 在Georgebecameill一句中, became是系词.
🗣️ 情景例句
I expect others to perform beyond their capacities.
我有时对别人的能力期望过高。
How many years have you been playing pingpong?
你打乒乓球多少年了？
What are you doing, Li Lei?
李垒，你在做什么？