1
sb's mamma
mamma 在此表示“母亲”，是较老派、亲昵的口语说法；现代英语更常用 mom 或 mum。
She wrote a letter to her mamma.
她给妈妈写了一封信。
妈妈
mammae — plural of mamma
先理解核心含义，再看它在真实句子里的用法。
妈妈
informal term for a mother
She wrote a letter to her mamma.
她给妈妈写了一封信。
非正式用语
雌性人类和其他哺乳动物分泌乳汁的器官,包括乳腺和乳头；乳房；乳腺。
The milk-secreting organ of female humans and other mammals which includes the mammary gland and the nipple or teat; a breast; an udder.
外观似乳房的附属云,可形成于多数云属的底部。
An accessory cloud like a mammary in appearance, which can form on the underside of most cloud genera.
The little girl ran to her mamma and hugged her tightly.
小女孩跑到妈妈身边，紧紧抱住了她。
Mamma, can you help me find my blue socks?
妈妈，你能帮我找找我的蓝袜子吗？
She waved goodbye to her mamma at the school gate.
她在学校门口向妈妈挥手告别。
mamma 在此表示“母亲”，是较老派、亲昵的口语说法；现代英语更常用 mom 或 mum。
She wrote a letter to her mamma.
她给妈妈写了一封信。
此义为解剖学或医学术语，指乳腺器官；复数形式常用 mammae。
The mamma enlarges during pregnancy.
乳房在怀孕期间会增大。
Not this
A dolphin is a mamma, not a fish.
Use this
A dolphin is a mammal, not a fish.
这里将“哺乳动物”误写成 mamma；mamma 意为“妈妈”或“乳房”，而 mammal 才是“哺乳动物”。应改成 mammal 以表达正确含义。
Not this
The doctor examined her mamma gland.
Use this
The doctor examined her mammary gland.
mamma 是名词，意为“乳房”，作定语修饰 gland 时应使用形容词 mammary（乳房的）。学习者常误用名词形式作定语，需改为 mammary。
Not this
The two mammae were talking outside the school.
Use this
The two mammas were talking outside the school.
当 mamma 表示“妈妈”时，复数形式是 mammas；mammae 是解剖学名词“乳房”的复数。这里指两位母亲，应用 mammas。
Focus on the distinctions below. Other candidates are kept compact until a reliable usage note is available.
离不开妈妈的人；妈宝男
At thirty, he is still a mamma's boy who calls his mother every hour.
他三十岁了，仍然是个妈宝男，每小时都要给妈妈打电话。
熊妈妈；护崽心切的妈妈
If you tease her kids, you'll have to deal with a mamma bear.
你要是逗她的孩子，就得应付一位护崽心切的妈妈。
妈妈最清楚；妈妈最懂
I know you don't want to, but mamma knows best.
我知道你不想，但妈妈最清楚。
副乳；多余乳房
A supernumerary mamma may develop along the embryonic milk line.
副乳可能沿着胚胎期乳线形成。
妈宝男（指过分依恋母亲的男人）
He's twenty-five and still a mamma's boy, always asking his mother what to do.
他二十五岁了还是个妈宝男，什么事都问他妈妈。
护崽的母熊（喻指保护欲极强的母亲）
Don't criticize her kids unless you want to face the mamma bear.
别批评她的孩子，除非你想面对发威的母熊。
女老大；有影响力的女人
She runs the whole business and is known as the big mamma around here.
她经营着整个公司，在当地被人称作女老大。
我的妈呀，我又陷进去了。
When the beat dropped, everyone sang along, “Mamma mia, here I go again!”
当节奏响起时，大家都跟着唱起来：“我的妈呀，我又陷进去了！”
Use mammae naturally, then get feedback on meaning, tone, grammar, and phrasing.
Revisit a common error or keep this word in your review list.
联想：婴儿吃奶时喊“mā ma”，mamma既指妈妈，也指哺乳的乳房，读音很像中文“妈妈”。
语域：informal 常见场景：家庭称呼、儿语、日常口语 mamma 作“妈妈”讲时是 informal 用法，多用于家庭生活或儿童称呼长辈，语气亲昵；在现代英语中不如 mom 或 mum 常用，可能带有些许过时或亲昵的色彩。
非正式用语；作“妈妈”义常见于口语，作“乳房”义带医学术语色彩。复数形式为 mammas 或 mammae。
Dictionary facts from ECDICT, WIKTIONARY.