He had begun to feel sleepy.

他已觉得困了。

《牛津词典》

I lay comfortably in his arms and I begin to feel sleepy as usual.

我舒舒服服地躺在他臂弯里，像往常一样开始犯困。

youdao

If possible, select a time to go to bed when you naturally begin to feel sleepy.

如果可能的话，选择感到困倦想睡觉的时间。

youdao

They will begin to feel very tired and sleepy.

VOA: special.2010.02.02

Professor Jim Horne, of the Loughborough University Sleep Research Centre, said the tendancy to feel sleepy in mid-afternoon was probably a legacy of our distant past.

BBC: How we go to sleep

Coloane Village still has a sleepy feel, while the coast leads on to Hac Sa Beach and Cheoc Van Bay.

BBC: Mini guide to Macau, China