Did you know that it matters where in a sentence you place that helpful adverb “only”? Consider this sentence:
Johnny only eats pickle pancakes on Saturdays.
The author of such a sentence almost certainly means that the only day on which Johnny eats pickle pancakes is Saturday, but the sentence actually can be (in fact the syntax requires that it be) read to mean that the only thing Johnny does on Saturdays is to eat pickle pancakes.
To convey the actual meaning, the sentence might read as follows:
Johnny eats pickle pancakes only on Saturdays.
But that sentence seems awfully formal, and in fact, it’s only a hair less ambiguous, as the “only” could still describe Johnny’s steadfast appetite rather than his timing. That is, the sentence “Johnny eats pickle pancakes only” makes sense and still means basically the same thing as the original troubling sentence. So, the clearest way to write the sentence with the desired meaning is as follows:
Johnny eats pickle pancakes on Saturdays only.
If the second variant seems formal, this last is downright stodgy, reading like something you’d find in a grammar primer from the 1950s.
Of course, in a sentence as ludicrous as this, it’s pretty clear what information the author wishes to convey. If Johnny does nothing all day on Saturdays but eat pickle pancakes, he probably wakes up a very sick boy on Sundays, if he wakes up at all. But sometimes the language really matters. I can imagine poorly written sentences causing contention when occurring in legal documents, for example.
So, a rule of thumb when using “only”: place it as close as possible to the thing it modifies. I think it’s generally better to place it before a noun and after a verb (depending on which it’s modifying). If you’re writing something fairly informal, you can of course be more flexible, but if you’re writing something that requires fine-tuned meaning, you should be careful where you place that tiny and easily-misplaced “only.”