This one is a standard check for most editors and is a very common source of confusion across almost all fields of writing – one is just as likely to encounter misuse in a scholarly journal as in a newspaper article.
Infer means to deduce or conclude something (i.e., from evidence, logic etc.).
Imply means to strongly suggest something without explicitly stating it.
A quick check that works in many (but not all) cases: it should be possible to ask what something is inferred from, but not by; it should be possible to asked what something is implied by but not from.
