<p>Is there a difference between the idioms "as" and "such as"?</p>
<p>For example:
For the past month, I have been doing things AS studying for the SAT and ACT.
and
For the past month, I have been doing things SUCH AS studying for the SAT and ACT.</p>
<p>Is there a difference? When should you use each one?</p>
<p>Yes, there’s a difference. “Such as” is often interchangeable with “for example,” although “such as” might sound better in some cases depending on the other words or if the preceding word(s) take(s) “such as” (i.e., if it’s an idiom).</p>
<p>“as” is used most often:
=In comparisons (“I am not quite as good as he at baseball”),</p>
<p>=As a subordinating conjunction (i.e. setting off adverb clauses): “As he was the only person in the room qualified to stitch up a wound, he rushed over to the scene of the accident to lend his assistance.” <– In these cases, “as” can usually be substituted with “because.”</p>
<p>=In idiomatic phrases: “as soon as,” “as well as,” etc.</p>
<p>It’s misleading to say that “such as” is interchangeable with “for example” because “such as” can be appended onto a clause, while “for example” requires either a new clause (use semicolon or new sentence).</p>
<p>By the way, this one is better: For the past month, I have been doing things SUCH AS studying for the SAT and ACT.</p>
<p>Your first example is grammatically incorrect. “Such” should be either before “as” or before “things.”</p>