What does とは mean in this sentence?

Question

Sentence:まさかあれだけやって起きんとは...
Translate: (I didn't expect) No matter what I do, he won't wake up.

What does とは mean at the end of this sentence?

Answer 1

When used at the end of a sentence, とは often shows surprise or disbelief. It is often translated as "To think that...". Here are some examples:

もう今年も１２月とは。
To think that it's already December this year too!

彼はこういうことをするとは！
To think that he would do something like this!

Do not confuse this with case particle と + topic marker は (彼とは付き合いたくない = I don't want to go out with him.). とは can also be used to define words as well (ブラックホールとはなんですか？ = what is a "black hole"?). とは only expresses surprise as a final particle.

With this, your sentence would roughly mean:

まさかあれだけやって起きんとは...
To think that he wouldn't wake up even though I did that much...