1. 表示“头发”或“毛发”的总称，是集合名词，不可数。如：
fair/dark hair 浅色头发；黑发
straight/curly/wavy /soft/coarse hair 直 / 鬈 / 波浪/柔软/粗糙的发
comb/brush your hair 梳头
She inherited our father's thick, wavy hair
她继承了我们父亲那头浓密的卷发。
I'll be down in a minute. I'm doing (= brushing, arranging, etc.) my hair .
我马上就下来。我在梳头呢。
do your hair 也有含义：做头发= fix your hair做头发
I wash my hair every night
我每晚都洗头。
He has black hair.
他一头乌发。
I get some grey hairs but I pull them out.
我有几根白发，但我都拔掉了。
Birds have feathers, not hair. 鸟有羽毛，而没有头发。
He had long hair when he was a teenager. 他十来岁时就留长发。
即使是表示部分头发，若意义泛指，仍不可数。如：
As people get older, they lose some hair. 人上了年纪就会掉头发。
但是，若表示一根或多根“头发”或“毛发”，则是个体名词，可数。如：
There's a hair in my soup.
我的汤里有根毛。
The rug was covered with cat hairs.
地毯上净是猫毛。
The police found two hairs there. 警察在那儿找到了两根头发。
The cat has left her loose hairs all over my clothes. 猫掉的毛弄得我衣服上到处都是。
下面一句中的第一个hair表总称（不可数），第二个hair为个体名词（可数）：
Her hair is black. Whenever she finds a grey hair she pulls it out. 她的头发是黑的，她只要发现有一根白发就将它拔掉。
She had a lot of make-up on and not a hair out of place.
她化了浓妆，精致得让人挑不出一丝瑕疵。
《柯林斯高阶英汉双解学习词典》
dark-haired
黑发的
long-haired
长发的
make sb's hair stand on end
惊吓某人；使某人毛骨悚然
This was the kind of smile that made your hair stand on end.
这是那种让人不寒而栗的微笑。
《柯林斯高阶英汉双解学习词典》
a chilling tale that will make your hair stand on end
令人毛骨悚然的故事
not harm/touch a hair of sb's head
不动某人一根头发；丝毫不伤害某人
hang by a hair/thread
(of a person's life 人的生命) 命悬一线；气若游丝；危在旦夕
not see hide nor hair of sb/sth
（一段时间）不见某人（或某物）的踪影
I haven't seen hide nor hair of her for a month.
我有一个月没见过她了。
He laughed and ran his fingers through his hair
他笑了，用手指拢了拢他的头发。
《柯林斯高阶英汉双解学习词典》
dry your hair弄干头发
lose your hair掉发
beautiful 长短 曲直 颜色 hair如：beautiful short curly yellow hair（漂亮的卷曲的黄色短发）
yellow的基本意思是“黄色的”，指某物体呈现出黄颜色，或指人的皮肤或毛发是黄色的，即“黄皮肤的”，此时常含有轻蔑的意味。地道说法：
blond/sandy hair 黄头发
blond hair and light blue eyes金发碧眼
She has fiar skin and sandy hair.她皮肤白皙，头发金黄。
类似白发也不常说white hair,而说：grey/gray hair
黑发也不常说：black hair，而说：dark hair
Strong colours would flatter her pale skin and dark hair
亮颜色更能衬托她的白皮肤和黑头发。
《柯林斯高阶英汉双解学习词典》
Grace had long straight dark hair which she wore in a bun.
格雷斯把一头长长的黑色直发盘成发髻。
《柯林斯高阶英汉双解学习词典》
He was a large man with thick dark hair.
他身材魁梧，头发浓黑。
《柯林斯高阶英汉双解学习词典》
The director wants a waif-like, teenage girl with long, dark hair for the role.
导演想要一个留着乌黑的长发、面黄肌瘦的十来岁女孩扮演这个角色。
《柯林斯高阶英汉双解学习词典》
She has short, thick black hair. 她有一头又短又厚的黑发。
注意几个限定词的顺序哦
2. hair 与动词 have 或 wear 搭配，含义稍有不同：用 have表示“有……头发”，用 wear 表示“留（做）……发型”。如：
He has golden hair. 他有一头金发。
black/blonde/brown/grey hair
黑发/金发/棕发/灰发
red hair 红发
fiar hair 也可以表达为：金发
grey hair 也指白发
gray hair灰白头发，白发（in AM, use 美国英语用 gray）
He slicked down his few remaining wisps of gray hair
他捋平了自己仅剩的几绺白发。
《柯林斯高阶英汉双解学习词典》
John wears his hair very long. 约翰留着很长的头发。
3. 下面两句均含有“理发”之意，但含义不同。如：
I shall cut my hair. 我将理发（自己给自己理发,不过这样变态的事情一般人做不来）。
I shall have my hair cut. 我将理发（请别人给我理发）。
I'm having my hair cut this afternoon.
我今天下午要去理发。
She had her hair permed.
她烫了发。
Her hair wants cutting.
她该剪头发了。
4. 与 beard（胡须）用法不同：一个人的胡须是 a beard，多个人的胡须是 beards，但不管是一个人还是几个人的头发却都是 hair。如：
These old men have long beards. 这些老人都有很长的胡须。
These young men wear long hair. 这些年轻人留长发。
hairdresser理发师;美发师;理发店;美发店
hair salon“发廊”
hair stylist“发型师”
hair style“发型”
Waist-length hair齐腰长发
Shoulder-length hair齐肩长发
Medium-length hair=中长发
Pony-tail
马尾辫
Slicked back
大背头
Buzz/Crew cut
板寸
Mohawk
莫霍克：两侧剃得超短，中间头发竖起来
