Hi folks!

I just cannot seem to find any grammar out there about this subject. A few years ago, one of my students showed me something her English teacher at her school had corrected. He had corrected a sentence that went "The one time I went to London it was raining" and changed it to "The once I went to London." I know what the mistake is (one time means the only occasion and once is an adverb which indicates frequency). I have seen something similar again and, as a result, I have put this short but simple explanation on a worksheet for A2 students but I was wondering if anybody has anything else they could add to clarify this.

 

So far, I have put this as a warning but they are not the best examples: Caution! It is not incorrect to use "one time" or "two times" to mean individual moments.

For example, "The one time during the week I have a bath is on Sunday." (The only time)

"The two times I have been to London it was raining." (both times)

 

I have seen one time and two times used in books where they have definitely been correct and the preferred usage but I cannot think of the examples or the exceptions and rules for them and Googling it does not seem to bear any fruit. Any ideas?

It may be an AE thing but we regularly use one time as a noun (time is a noun, one is an adjective?).

 

So aren�t we just modifying "time"

 

 https://kris-spisak.com/writing-tip-onetime-vs-one-time/

Thanks Douglas.

That is quite useful although I am not too sure about the sentence:  One time, I wore a purple sparkling cape because my bookstore employer dictated it on the night of a Harry Potter midnight release. In that case I would have written, Once, I wore a purple sparkling cape because my bookstore employer dictated it on the night of a Harry Potter midnight release.

The one-time adjective, though, is increasingly common. And the fact that this writer is comfortable using "one time" instead of "once" just shows how this is not as clear cut as the grammar books make it out to be.  

I like your question!

For me, "One time" or "The one time" could be replaced by the phrase "On (the) one occasion", whereas "once" could be replaced by "a while ago" (it doesn�t have to refer to a unique occasion). So there is a lot of crossover. I would perhaps argue that Once / One time can both begin a sentence without changing the meaning, but "The one time" is more specific than once.

Your Harry Potter example above seems to fit both criteria, in my opinion - it happened one single time a while ago.

The one time I visited Denmark, it rained all week. (I have only been to Denmark once.) / Once I visited Denmark, and it rained all week. (On one visit to Denmark it was very rainy, but there may have been other non-rainy visits too.)

Thank you Douglas and FrauSue. Yes, it does indeed look as though we can use one time, and once, interchangeably when talking about a single moment or occasion. Whereas once and twice should not be confused with frequency when talking about routine. (I go to the swimming pool twice a week. I have a shower once a day. The train goes once every 30 minutes. etc.) All the same, seeing that correction threw me a little, and the lack of guidance in the grammar books was a surprise. 

Thank you folks!  

You could add as an exception that we only use "the one time" for emphasis, to show aggravation or surprise.

You are absoutely right that �once� and �one time� can be used interchangably in most other cases.

But for emphasis...

"the one time -ONE TIME - that I skipped school...and they went off on  day trip! Can you believe my luck?"