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
I agree.
我同意。
John has extracurricular activities. He's on the football team.
约翰有课外活动。 他参加了足球队。
The world had to wait almost another 100 years for the Channel Tunnel.
世界不得不再等将近100年才看到海峡隧道竣工。