Level of detail when reviewing the language of a low quality paper I am currently reviewing a computer science conference paper. I like to give constructive feedback both related to the content as well as for language issues, such as typos or grammatical mistakes.

The paper I'm currently reviewing has significant language flaws. Mentioning each and every typo, wrong word order, and grammar issue would take me about an hour.  The paper will likely be rejected anyway, so I am not sure if these language suggestions will even be used. It would be different if the paper were likely to be accepted, because improving the language would further improve the quality of the paper.

Does it make sense to give thorough and detailed feedback on a poorly written paper's language quality in a review if the paper will likely be rejected?
From Alan Jay Smith's The Task of the Referee:


  Refereeing a paper can require considerable time and effort; don't waste that effort on a detailed critique of a badly flawed paper that can never
  be made publishable. Finding one or more fatal and uncorrectable flaws excuses the referee from checking all subsequent details.


The trick is to determine what is indeed "fatal". If you believe that your corrections have some non-trivial chance of improving a published paper at some point (possibly in a less-competitive venue), go ahead and make them, as you are contributing something to the body of literature. Otherwise, do not waste your time.

As an addendum, you are not a copyeditor, but a scientific reviewer. Ways to deal with papers with many language/grammar issues include:


If grammatical errors are very numerous, point out classes of errors, instead of individual ones.
Focus on errors which actually obscure scientific meaning, and let ones which are merely poor or nonstandard style go.