1
a pillowcase
pillowcase 是可数名词，表示单数时用不定冠词 a。
He bought a pillowcase for his bed.
他给床买了一个枕套。
枕套
pillowcases — plural of pillowcase
先理解核心含义，再看它在真实句子里的用法。
枕套
a cover for a pillow
He bought a pillowcase for his bed.
他给床买了一个枕套。
一种可洗涤、易拆卸的枕头布套。
A washable, easily removable cloth cover for pillows.
枕头的床上用品套
bed linen consisting of a cover for a pillow
I need to wash the pillowcase because it has a stain.
我需要洗一下枕套，因为上面有污渍。
AI contextual example
She bought new pillowcases to match her bedroom curtains.
她买了新枕套，用来搭配卧室的窗帘。
AI contextual example
The hotel changes the pillowcase every day for each guest.
这家酒店每天为每位客人更换枕套。
AI contextual example
the burglar carried his loot in a pillowcase
窃贼将赃物装在枕套里。
WordNet
pillowcase 是可数名词，表示单数时用不定冠词 a。
He bought a pillowcase for his bed.
他给床买了一个枕套。
pillowcase 的复数形式是直接加 -s。
These pillowcases need to be washed.
这些枕套需要洗了。
Not this
I bought new pillowcase.
Use this
I bought a new pillowcase.
pillowcase 是可数名词单数，前面需要不定冠词 a；汉语没有冠词，所以容易漏掉，加上 a 后句子才完整。
Not this
I have two pillowcase on my bed.
Use this
I have two pillowcases on my bed.
two 后接可数名词复数，pillowcase 的复数是 pillowcases；漏掉复数后缀 -s 不符合英语数的一致规则。
Not this
Please put the pillowcase in the pillow.
Use this
Please put the pillowcase on the pillow.
pillowcase 是套在枕头外面的，所以用介词 on 表示“套在……上”；用 in 会被理解成“在枕头里面”，语义不通。
Focus on the distinctions below. Other candidates are kept compact until a reliable usage note is available.
干净的枕套
She puts a clean pillowcase on the pillow every week.
她每周给枕头换上干净的枕套。
换枕套
You should change the pillowcase more often.
你应该更频繁地更换枕套。
棉质枕套
I prefer a cotton pillowcase because it is soft and breathable.
我更喜欢棉质枕套，因为它柔软透气。
缎面枕套
Satin pillowcases are said to reduce hair breakage.
据说缎面枕套能减少头发断裂。
带拉链的枕套
This pillowcase with a zipper is easier to remove and wash.
这个带拉链的枕套更容易取下清洗。
配套的枕套
The sheets and pillowcases are sold as a matching set.
床单和枕套作为配套的一套出售。
Use pillowcases naturally, then get feedback on meaning, tone, grammar, and phrasing.
Revisit a common error or keep this word in your review list.
pillow(枕头)+case(套子)=枕套，想象给枕头穿上一件衣服。
语域：neutral 常见场景：居家、购物、洗衣 pillowcase 通常用于日常家居语境，多指套在枕头外面的布套；比较常见于谈论床品、清洗或购物等场景。
pillowcase 的 -case 读 /keɪs/。case、suitcase、briefcase 直接含有 case；face、place、base 的结尾同样读 /eɪs/，与之押韵。注意拼写相近的 vase 在英式英语中读 /vɑːz/，phase 读 /feɪz/，都不与 -case 押韵。
Dictionary facts from DICTIONARY_API_DEV, ECDICT, WIKTIONARY.