I was unable to attend because of a previous engagement.

我因有约在先，无法出席。

《牛津词典》

I was unable to move on my feet.

我的脚不能动。

youdao

Being a child, I was unable to understand him.

作为一个孩子，我无法理解他。

youdao

I paid off as much as I could." Zahwe Samouni had little cash left and was unable to find enough construction materials, but she managed to build a two-room cinderblock house.

VOA: standard.2010.01.02

Having overdone it, I was unable to eat and my stomach was in knots.

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"Against the lefties I was unable to make my pitches, " Kuroda said through a translator.

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For a long time, in the early hours of the morning, I was unable to sleep.

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