spare与to spare的区别

spare 名词多余的，动词节约
to spare 过剩，是短语

spare
[spɛə]
vt.
节省, 节约, 舍不得, 吝惜
She never spares the butter when baking.
她煎饼时从不吝惜黄油。
抽出, 让给, 分出, 匀出, 腾出
Could you spare some time to come to our art exhibition?
你能抽出时间来看看我们的画展吗?
省去, 免除
The doctor tried to spare him from pain.
医生尽力使他免受痛苦。
饶恕, 赦免, 不伤害
The *er was spared.
那个囚犯被赦免了。
adj.
多余的; 备用的
Do you carry a spare wheel in the back of your car?
你在车后带了一个备用的轮胎吗?
薄弱的, 瘦的
His tall and spare frame cut an impressive figure.
他那修长的身材给人以深刻印象。
n.
备用零件; 备用轮胎
I'll show you where the spares are kept.
我会指给你看放备件的地方。
to spare
过剩,有余
Examples:
She (only) just caught the train with one minute to spare.
她差一点儿没赶上那趟火车.
Try to spare her as much distress as possible when you tell her.
你告诉她的时候, 尽量不要让她伤心.
Do you have any sugar to spare?
你的食糖有富余吗?
---解释来自金山词霸2008

to spare 是 spare 的不定式形式
意思上没有任何区别 只是在句子中的成分不一样
spare 作为动词 可以做谓语
作为形容词 只能做表语
to spare 只能做（目的）状语
当然它有时候也可以做主语 表示 要去spareXX
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