用英语怎么说大葱

"大葱" (dà cōng) in English is called "green onion" or "scallion".
It is called scallion because it is a young onion which does not bulb out, and the green part is used for seasoning.
The word "scallion" comes from the Latin word "ascon" meaning "onion" which is used to describe the green onion that does not form a bulb.
Examples:

I love to add green onions to my omelette.
(我喜欢在我的煎蛋里加入大葱)
The scallions give the soup a nice mild onion flavor.
(大葱给汤带来了温和的洋葱味)