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
Yes, there is.
有，有心事
Poor without debt is better than a prince.
穷人无债胜王子。
climbed up the dunes, and sat down on a road.
爬上沙丘，最后停在路上。