许多语法家都将此类句式中的形容词分析为状语，修饰谓语。又例如：

He died young.他英年早逝。

Tomatoes can be eaten raw.番茄可以生吃。

▲ 但也有的语法家持不同观点，如薄冰语法就把They married young.中的young分析为“主语补足语”，与married一起构成复合谓语。此类句式会用既可，不必过于纠结。

我个人认为;equal是主语补足语，equal是形容词，句子是被动结构。

http://ask.yygrammar.com/q-32387.html

All men are created equal.

=They are equal when they are created

人人生而平等。

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解析如下：

以上属于形容词作状语用法，表示动作发生时，主语所处一种状态，不是所有动词都可以这样使用，这样使用的动词通常是那些表示位置移动变化，姿态动词或者生与死的瞬间行为动词。

备注：形容词表示谓语动词动作发生时，主语所处的一种状态。

live, die,return，leave， go，come，arrive，pass,start,wander，lie,等。其具体的结构形式主要有以下几种：

(1)动词+形容词

He left this morning very gay．

=He was very gay when he left this morning．

上午离开时，他很开心。

She lay there motionless．

=She was motionless when she lay there．

她躺在那儿一动不动。

(2)动词+名词

She left a shy girl and returned a young mother．

=She was a shy girl when she left and a young mother when she returned．

她离开时还是一个害羞的女孩，回来时却是一位年轻的母亲。

He lived a hero and died a martyr．

=He was a hero when he lived and(he was省略）a martyr when he died．

他生前是英雄，死后为烈士。

(3)动词+介词短语

He died in despair．

=He was in despair when he died．

他死时非常绝望。

He left in tears．

=He was in tears when he left．

他离开时眼含泪水。

He ran into the room out of breath．

=He was out of breath when he ran into the room．

他冲进房间时已是上气不接下气。

(4)动词+分词（短语）

They lay there chatting．

=They were chatting when they lay there．

他们躺在那里聊天。

He wandered wondering．

=He was wondering when he wandered．

漫步时，他在冥思。

He came home exhausted．

=He was exhausted when he came home．

他回家时已是筋疲力尽。

(5)动词+what从句

He returned home what he had always been．

= He was what he had always been when he returned home．

回家时，他还是老样子。

备注：以上结构很少有否定形式，但偶尔也出现否定形式。这时，要特别注意否定的形式在前，意义在后，即否定后移现象。

She didn't arrive accompanied by her daughter．

=She was not accompanied by her daughter when she arrived．

她抵达时不是由她的女儿陪同。

He didn't pass noticed．

=When he passed he was not noticed．

他路过时没人注意。