He was tired because he had had insufficient sleep.是什么意思？

He was tired because he had had insufficient sleep.

他很疲倦,因为他未睡足。

he

pron. 他，它，一个人；n. 雄性动物；

例句
Logic had prevailed and he had abandoned the idea.
最终理智占了上风，他打消了那个念头。

was

v. 用来表示某人或某物即主语本身，用来表示某人或某物属于某一群体或有某种性质（ be的过去式 ），在，存在，不受干扰；

例句
There was a terrible sadness in her eyes...
她眼神中流露出深深的悲伤。

tired

adj. 疲倦的，困倦的，对…不耐烦的，陈旧的；v. （使）疲劳（ tire的过去式和过去分词），对（做）某事感到厌倦；

例句
He's tired so I'll make allowances for him.
他很累，所以我会体谅他。

because

conj. 因为；

例句
5,000 people die every year because of accidents in the home...
每年有5,000人死于家中的意外事故。

had

v. 有（ have的过去式和过去分词 ），（亲属关系中）接受，拿，买到；

例句
He claimed that his parents had abandoned him...
他声称父母遗弃了他。

insufficient

adj. 不足的，不够的，绌，亏短，支

例句
There was insufficient evidence to convict him.
没有足够证据给他定罪。

sleep

vi.& link-v. 睡，睡觉；vi. 睡，睡觉，睡眠状态；vt. 为…提供床位，提供住宿，以睡觉打发日子；n. 睡眠；

例句
Their sleep is regularly disturbed by the sound of gunfire as criminal gangs settle their nightly accounts.
他们经常被黑帮每晚火拼的枪声所吵醒。