Apart from Federer, I have not seen a stronger player.
The sentence is grammatically incorrect. Why is it incorrect?
Apart from Federer, I have not seen a stronger player.
The sentence is grammatically incorrect. Why is it incorrect?
I don't think there's an error in that sentence. It's acceptable to start a sentence with a prepositional phrase, including ones like "except for" and "apart from".
Here is a page with a more thorough explanation of prepositional phrases, and when and where they can be moved.
This sentence says clearly and grammatically correctly that you have just been watching the second strongest or possibly strongest player you’ve ever seen, and that you have also seen Federer, who is the only player you have seen who may have been stronger.
This is what traditionalists call a misplaced modifier. I use the word "technically" below to indicate the traditional perspective, the one we can read about in textbooks written for young people.
When a modifying phrase is next to a noun phrase, it technically modifies that noun phrase.
In this case Apart from Federer is a modifying phrase. It is next to I, so technically it modifies I. It therefore seems to indicate that I is apart from Federer, and this is clearly not the author's intent. The author wants to describe the object of the comparison.
If someone has called the sentence "incorrect," they are probably thinking of this traditional rule.
In practice, "misplaced modifiers" rarely cause genuine confusion. Native speakers "misplace" modifiers all the time, and their audience usually understands the intent. The meaning of the Federer sentence is perfectly clear.
That said, the careless placement of modifiers can cause miscommunication, often with comic results. Consider the following:
Crying and screaming throughout the funeral, the dead man was mourned by his friends and family.
A dead man was crying and screaming? Your audience will no doubt get the point, but some of them may be inclined to laugh at an inappropriate moment.
The sentence is grammatically incorrect.
I don't think this statement is true.
The sentence may (or may not) be semantically incorrect based solely on the context.
In case it is not preceded (expectably immediately) by a reference to another player (that is, the better part is a comparison to Federer himself), then it absolutely is.
Otherwise it is perfectly legal and comprehensible.
While I like Jeffrey Carney's answer (and upvoted it), I will write my own because I believe one thing about the question should be made clear. While the questioner's sentence may seem confusing or ambiguous to some, it is not grammatically incorrect. It would be clearly understood by native speakers under most circumstances.
However, as a matter of style, this sentence may not constructed in the clearest way. What you see in the sentence is possibly a misplaced modifier[1]. Supposedly, one could understand the phrase "Apart from Federer" to refer to the speaker ("I"), but in this sentence I think such a misunderstanding would be highly unlikely. One can find examples of far more egregiously misunderstandable sentences at the sources linked in the footnotes. Additional sources to understand misplaced modifiers are at [yourdictionary (dot) com][2], and [opentextbooks (dot) org][3].
The Walden Univ source describes misplaced modifiers as
When a modifier is ambiguously or illogically modifying a word, we consider it a misplaced modifier.
And, the yourdictionary description:
It’s important for modifiers to stick close to the word or words they’re modifying. When they stray too far, they become misplaced modifiers — and if they get too far, it may look like they’re modifying something else.
You will notice that none of the resources linked puts modifier placement in the "rules to obey" column, as we have with some other grammatical instances. What is important in each description is that the modifier be placed for clarity of understanding. A pedant might take issue with the placement of "Apart from Federer", because it is not directly adjacent to "a stronger player". However, since, in this usage the "apart from" phrase clearly modifies "a stronger player", it would not be misplaced. If one were concerned for absolute clarity, with no chance for misinterpretation, then perhaps:
I have not seen a stronger player, apart from Federer.
or
I have not seen, apart from Federer, a stronger player.
However, personally I find both cases to be more uncomfortable and lacking the immediacy and dynamic exclamatory style of the original. As I said above, one can easily find examples of truly misplaced modifiers, whose placement would lead to gross misunderstanding or confusion. But I don't think this is one.
[1]: https://academicguides.waldenu.edu/writingcenter/grammar/modifiers
[2]: https://examples.yourdictionary.com/examples-of-misplaced-modifiers.html
[3]: https://www.opentextbooks.org.hk/ditatopic/4537
In this very example it is perfectly clear what the speaker wants to communicate. But let's exchange I for we.
Apart from Federer, we have not seen a stronger player.
Now it is not perfectly clear anymore: have we not seen any stronger player, except for Federer, or has none of us, except for Federer, ever seen any stronger player.
I think this is the reason why those types of constructions are not seen as 100% correct.