1
extra + adj.
extra 在此作副词，修饰形容词，表示‘格外、特别’。
Be extra careful when crossing the street.
过马路时要格外小心。
Be extra careful when crossing the street.
过马路时要格外小心。
异常；格外
unusually or exceptionally
The hotel charges extra for a room with a sea view.
酒店对海景房额外收费。
She worked extra hard to finish the project on time.
她格外努力地工作，以便按时完成项目。
If you stay late, you'll need to pay extra for the overtime.
如果你待到很晚，你需要为加班额外付费。
extra 在此作副词，修饰形容词，表示‘格外、特别’。
Be extra careful when crossing the street.
过马路时要格外小心。
extra 修饰副词，同样表示程度超出正常。
She can run extra fast.
她能跑得格外快。
extra 在此作副词修饰动词 pay，表示‘额外（地）’。
If you want a larger size, you will have to pay extra.
如果你想要大一号的，你得额外付费。
Not this
He extra worked hard.
Use this
He worked extra hard.
extra作为副词时应放在所修饰的形容词或副词之前，而不是动词之前。
Not this
He works extra.
Use this
He works extra hard.
extra作为副词时不能单独使用，必须修饰一个形容词或副词来表达程度。
Focus on the distinctions below. Other candidates are kept compact until a reliable usage note is available.
格外小心；特别仔细
Be extra careful when you cross the road.
过马路时要格外小心。
格外特别；非常特别
We prepared an extra special dinner for her birthday.
我们为她的生日准备了一顿非常特别的晚餐。
格外努力；特别用力
She worked extra hard to finish the project on time.
为了按时完成项目，她工作得格外努力。
特别长；格外长
The meeting ran extra long, so I missed my train.
会议开得特别久，所以我错过了火车。
特浓；格外浓
He ordered an extra strong cup of coffee.
他点了一杯特浓的咖啡。
Use extra naturally, then get feedback on meaning, tone, grammar, and phrasing.
Revisit a common error or keep this word in your review list.
想到 XL（extra large）就是“格外大”，所以 extra 加在形容词前表“格外”。
语域：informal 常见场景：日常口语、广告宣传、非正式书面语 作为副词表示“格外、异常”时，通常用于日常口语或非正式场合，如“extra careful”；正式写作中较少使用，更常用“especially”或“unusually”。
Used to mean 'more than usual' or 'in addition'. Cannot be used before a noun alone; use 'extra' + adjective + noun.
Dictionary facts from DICTIONARY_API_DEV, ECDICT, WIKTIONARY.