Please relinquish.

I suggest: "He tries to keep up with his classmates."

Search for "keep abreast of his classmates" and it's only used in this sentence. As you said, abreast means "being up to particular standard or level especially in being up to date in knowledge; "kept abreast of the latest developments"; "constant revision keeps the book au courant"; "always au fait on the latest events"; "up on the news"" So, it doesn't match the Japanese and wouldn't be used in this context. I suggest adding an example with a doctor.

Here is the phrase in The Free Dictionary

*abreast of someone or something
1. Lit. keeping even with someone or something. (*Typically: be ~; get ~; keep ~; Stay ~.) I had to run hard to stay abreast of Sally.
2. Fig. knowing the news about someone or something. (*Typically: be ~; get ~; keep ~; Stay ~.) The press corps has to keep abreast of the president.
See also: abreast
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My personal opinion is that "to keep abreast" sounds more formal,and to keep up more colloquial.

Please remove label "Needs native check".

I think it's also important to ask "would anyone say that? (or write that?)" If not, then it's not natural English.

And I have the feeling that "keep abreast of" is almost always about information nowadays.

> Why not add this as an alternate translation of the Japanese?

I guess it's because I told him not to translate unowned Japanese sentences.

Maybe I shouldn't have said that. When the English sentence is not wrong and just old-fashioned or a bit awkward, it might be a good idea to add a better one as a translation of the Japanese, even if it's an orphan sentence.

I still believe that, if the English is wrong and the Japanese is unowned, you'd better simply ignore the pair. The possibility is higher that the Japanese is also not very good.

Hi, Tommy-san, I think your advice is really well-considered. ☺
Ich glaube, was du über den Umgang mit den japanisch-englischen Satzpaaren geschrieben hast, solltest du auch an die Pinnwand schreiben. Es erscheint mir logisch und gibt eine gute Orientierung.

The reason why I didn't just add an alternative actually is because I believed that this sentence was wrong. I'm still not convinced that it's natural. Unless proven otherwise, I'm not sure that anybody would say that. I'm not even sure that people would have said that a hundred years ago. I think that we should try to make the Tanaka corpus sentences as natural as possible. This sentence was probably not written by a native and there's no reason to have so much respect for this unnatural sentence in my opinion.

>The danger of this, of course, is that non-native speakers >don't realize what's currently good and what's not, so expose >themselves to unnatural language usage.

Absolutely.

@WestofEden. I believe that you don't read books, and that is why the sentence sounds unnatural to you. Which brings me to the question, what happens in 20 years when some of our "current" sentences appear "unnatural" ?

We'll tell the new contributors that they can't speak proper English.

Here is my disclaimer: I am over 60 years old and everything I have heard or remember hearing in my life is current English as far as I'm concerned.
I also confess to reading English literature written before the 20th century and it all belongs to the treasury of the English language.

On a more serious note, I didn't find many examples of this expression being used like this. This is one of the closest ones: "But nowadays, the average man is interested in a great variety of subjects, his natural wish to keep abreast of his neighbours leads him into many different paths of thought." I guess this might have been fine in the 19th century.

I agree with you Dejo that correct English isn't just current English. I just wasn't sure that this had ever been correct. I accept that this may be correct.

Here's an example from Google books 2013
"As new advertisers enter your market, it's important to keep abreast of your competition. ..."

OK then.

And thank you for showing me that this could be a natural sentence.

You're welcome☺

And I'd like to thank WestofEden, too, for telling us that there's someone who think this is unnatural. This kind of discussion is quite useful for learners.