The toy almost choked the baby to death.

【翻译】那个玩具差点把婴儿呛死了。

句中没有不定式，to death 是个介词短语，to 是介词，death 是名词，哪来的不定式？to 的一个用法是表示“结果”，说明谓语动词导致的结果。尤其跟death 连用，构成词组 to death （致死；还比喻“程度极大”）。又如：

The seedling was frozen to death.

幼苗被冻死了。

The slave was strapped to death.

这个奴隶被鞭打死。

The murderer was shot to death at once.

谋杀者立刻被一枪打死。

The criminal was condemned to death.

这个罪犯被判死刑。

The burglar was sentenced to death.

那个窃贼被判死刑。

Being alone with a baby all day bored her to death.

整天一个人和一个婴儿在一起使她厌倦死了。

He scares teams to death with his pace and power. 

他的速度之快、力量之大让其他队胆战不已。

来自柯林斯例句