Copulas
n. 系动词（如be,seem,appear等）, （命题主词与谓词间的）连系( copula的复数形式 )
🗣️ 情景例句
Please pass me a knife.
请把刀递给我。
Our clients are very critical on quality.
我们的客户对商品的质量是很挑剔的。
The weather can be quite warm in autumn.
秋天，气候十分暖和。