ことか・
An outcry, not a question: "how worried I was!", "the times I've told him!". A question word opens it, ことか closes it, and nobody is expected to answer.
I can't count the times I thought I couldn't go on.
How long that week felt, waiting for the results.
How to form it
Question word + plain form + ことか／ことだろう
The question word is どんなに, どれほど or どれだけ (how much), or one that counts, like 何度 or 何年 (how many). A な-adjective takes な: どんなに大変なことか.
- Before it
- What you felt or went through, mostly in the past: 心配した, うれしかった, 待った, 言った.
- Which ending
- ことか is the outcry. ことだろう is quieter, as if thinking back. ことでしょう is polite, for speeches and letters.
- Said about
- Your own feelings. About someone else you are imagining theirs: "how pleased she must have been".
- Where you'll meet it
- Novels, essays, letters, speeches. Out loud only when feelings run high: relief, gratitude, or the end of your patience.
In use
Thank goodness you're safe. You have no idea how worried I was.
The times I've told him not to be late!
How happy my mother must have been when she heard I had passed.
I cannot tell you what a strength your warm support has been to us.
Two things to know
か doesn't ask anything
It looks like "how many times did I…?", but no number is wanted: it was more than you can say. English "How …!" is rare now, so it often comes out as "I can't tell you how…" or "so many times".
It needs the question word
Not said: とても
(How worried I was!)
どんなに心配したことか. In plain words: 本当に心配した.
Close neighbours
ことといったらN3
The same amazement told as a story about one thing. No question word, and the sentence goes on or trails off.
You wouldn't believe how small this room is. There isn't even space to open a suitcase.
ものだN3
Quiet wonder at one thing, with no question word.
That tiny little kid, in college already. How time flies.
ことにN3
The feeling named calmly at the start, then the fact.
Fortunately, none of the passengers were hurt.
Check yourself
1What does this mean?
この
Choose an answer to see why.
2Which one fits?
一人で
Choose an answer to see why.
More detail
With no question word, ことだろう is only a guess made with sympathy, common in letters.
My parents must be so worried by now.
In books, なんと does the work of the question word.
How beautiful the sunsets are in this town.
More sentences
I can't tell you what a comfort my family's support was through the long treatment.
How much my child's smile has kept me going all these years.
How my legs shook the first time I stood on a stage.
How I longed for the food of my home town.