小时候的英文：
in one's childhood
when one was young
as a child

参考例句：

A pet lamb makes a cross ram.
蛮横的公羊是小时候宠坏的。

We were not allowed to quarrel with one another as children.
我们小时候是不许吵架的。

Early in life he learned to play the violin.
我小时候学过小提琴。

When my father was a child he suffered hunger and cold and was often cursed and beaten.
我爸爸小时候挨饿受冻，还经常挨打挨骂。

It was familiar; he had seen things like that when he was a little boy.
这是不足为奇的;他小时候也见过这类事情。

When I was young, I came to Beijing but my only impression was of sugarcoated haws on a stick.
小时候我来过北京﹐不过印象里只有糖葫芦。

He always said he'd be buried near the sundial he used to climb upon when he was a child
他老是说要把他埋在他小时候爬上爬下的日晷旁边。

I had curly hair when I was little
我小时候是鬈发

When I was a child, I used to tree.
我小时候总喜欢爬树。

When I was small, I once read a jingle.
我小时候念过一顺口溜。

one是什么意思：
num. 一；同一个、最重要的一个
det. 代替a或an，表示强调；某位（用于不太熟悉之人的姓名之前）
pron. 任何人；一个人；一个事物；其中的一个人

One, Taipei, one way.
台北单程票一张。

This one is not a spoof.
这个就不是开玩笑了。

One and one make(s) two.
一加一等于二。

childhood是什么意思：
n. 童年；童年时期

These diseases are incident to childhood.
儿童易患这类疾病。

She had a happy childhood.
她曾有过一个幸福的童年。

Childhood is golden and pure, for which the funs of childhood provide sufficent evidence.
童年，是金色而无杂质的，童年的桩桩趣事就是最有力的见证。

when是什么意思：
conj. 在…时候；在…之后；一…就；考虑到，既然；虽然，然而
adv. 什么时候，何时；在那时；当时
pron. 什么时侯；何时
n. 时间

Tact is the art of recognizing when to be Big and when not to be little
知道何时应该宽宏大度,何时不应量小器微,是谓练达

Time flies when you are online.
上网的时候时间过得飞快。

When you see him, book!
当他见到他时，迅速离开！