洋葱和卷心菜到底是不是可数名词

洋葱和卷心菜到底是不是可数名词
就是onion和cabbage.
在什么时候做可数名词,在什么时候做不可数名词

名词 onion
■若当作一种植物看待,为可数名词,指“一根洋葱”“一个洋葱头”等.如：
The onions are beginning to sprout up.洋葱正在抽芽.
There were stings of onions hanging on the wall.墙上挂着一串一串的洋葱.
■若指作为菜吃的“洋葱”“洋葱头”,有时可数,有时不可数.如：
(1) 可数用法：
Chop an onion finely.把洋葱切细.
Onions have a strong odor.洋葱气味刺鼻.
I like liver and onions for dinner.晚餐我喜欢吃肝和洋葱.
Shall I use oil or butter for frying the onions?我用普通油还是黄油来炒洋葱呢?
(2) 不可数用法：
The soup tastes of onion.这汤有洋葱味.
There is too much onion in the salad.色拉里的洋葱太多.
You’ve put too much onion in the salad.你的色拉中洋葱太放多了.
名词cabbage
■作为植物的“卷心菜”,指“一棵洋白菜”“一棵卷心菜”,通常可数.如：
The cabbages germinated within a week.白菜一星期内就发芽了.
He planted a row of cabbages.他种植了一行洋白菜.
The cabbages were stored in the basement.包心菜储藏在地下室里.
The leaves of a cabbage can be green,white or purple.卷心菜的菜叶有绿色、白色或紫色的.
Two cabbages,three pounds of tomatoes and twelve oranges.两棵白菜,3磅西红柿,12个桔子.
Given better attention,the cabbages could grow even faster.白菜如照管得好会生长得更快.
■作为疏菜吃的（尤指切碎的或煮熟的）“卷心菜”“卷心菜叶”,不可数.如：
Mother often makes dumpling filling with cabbage.妈妈常用卷心菜做饺子馅.
Finely chop the cabbage and cook it in boiling salted water.把卷心菜切碎,放进沸腾的盐水中煮.
Coleslaw is a kind of salad made of finely chopped cabbage and mayonnaise.克思罗沙拉是用切碎的圆白菜和蛋黄酱做成的.
【谚语】Some persons like to eat radishes,others prefer cabbages.萝卜白菜各有所爱.