َAre these sentences correct?

I don’t say If I have written these sentences or I got them from a book whose author is a native speaker of English, because I know by revealing that, your answers will be remarkably affected. So, just go with them as they are:

Are the following sentences correct? And sound quite normal to your ears?

1- Who did you come to the party with?
2- I don’t know **who **he gave the book to.
3- That is the woman **who **I was talking to.
4- **Who **did you get that from?
5- Do you have any idea **who **he sold his car to?
6- That is the person **who **I got the information from.

They all sound appropriate to me; several would be better recast in “to whom” form.

It does bring to mind the single deadliest piece of snark I’ve ever acquired, from one of the 1940s writers: “‘Whom are you?’ he asked, for he had been to night school.”

I’d advise reading this usage note. In short, in formal writing, you’d be advised to use “whom” whenever it’s in the objective case, for example (your examples) as the object of prepositions. “Who” in each of your sentences should probably be, in formal writing, “whom.”

But if the writing is informal, “who” is fine. “Whom” is increasingly rare in English, going the way of “thou.”

They all sound accurate. On the whole, native speakers don’t understand the usage of “whom” and typically use it at random to sound fancy.

#6 seems quite awkward – I would say “that’s the person who gave me the information” which avoids ending in a preposition and using the informal-sounding verb “got”. But, many native speakers write badly.

In traditional grammar, they should all have “whom”. A couple of then (2 and 6) even sound better to my ears that way. But the form is dying and I don’t anyone who will miss it. (And all too many hypercorrectors would say “whom will miss it”). Between you and I, just go with the flow.

I’d put nearly all “correct” uses of whom (excepting ‘for whom’ and ‘to whom’ uses) in the dustbin without a quiver. There’s no way for it not to sound affected and stilted, even in formal writing.

All of those sentences are grammatically incorrect, but if they were rephrased for the sake of proper grammar, the speaker in most everyday contexts would come off as pompous or at least stiffly pedantic. All of those sentences have a misapplied “who” in a sentence that ends with a preposition.

If I was (were) hanging out with a buddy over a couple of beers and blurted, “That is the woman to whom I was talking,” he’d likely give me the equivalent of that raised-eyebrow smiley.

“From whom did you get that?”

“With whom did you come to the party?”

“Do you have any idea to whom he sold his car?”

I might speak in such a stilted manner to evoke a laugh, but to do it as a way of life would make me sound like a serious weirdo.

And Hari Seldon, I know you were just joking, but “Between you and I” makes me wince no matter what.

Little known fact:
Roger Daltrey and Pete Townsend originally named their group, “The Whom”, but realized Americans would never understand the name and changed it to “The Who”.

One of my favorite books was Hemingway’s American version of “For Who The Bell Tolls” - it got rid of lots of unnecessary words.

In typical spoken English, #3 and #6 have too many words. “That’s the woman I was talking to”, and “That’s the person I got the information from”. Subordinative conjunctions like “that” and “who” tend to get dropped quite a lot, even in written English. The general rule of thumb (not a formal style rule) is that if leaving the word out does not negatively impact clarity or rhythm, then the word can be left out.

They’re all informal and many of them aren’t constructions that I’d typically use, but they’re all perfectly cromulent for spoken English. I’m more concerned that you chose to start a sentence with “and”.

It’s been a part of English since at least the 1600s, as it’s common in the KJV Bible. The bigger problem is that the sentence in question is a sentence fragment. This is fine if the fragment was intentional. But I would advise those learning English to avoid sentence fragments.

And, yes, I used “but” and “and” to start a sentence on purpose.

In all six sentences, “who” serves as the object of a preposition (to, from, with). That means it’s in the objective case and should therefore, technically, be “whom” in formal writing. However, many grammar books will tell you that using “who” where you technically should use “whom” is not a serious offense, if it even counts as an offense at all; it’s far worse to do it the other way around, and use “whom” where “who” would be correct. So, at least in everyday, informal contexts, I’d say all six sentences are fine the way they are.

Incorrect sentences. For the Subject, doer of the action, use Who. The Object, receiver of the action, use Whom. That’s the rule. No nonsense about what it sounds like, feels like, believe, guess. There are rules. It is not haughty or supercilious to follow them. We all know you can tell an educated person from an uneducated one by how he/she answers the phone: “This is she” or “This is her” respectively. Reverse the syntax. “She is this speaking” or “Her is this speaking?”
#1. “With who did you come to the party?” Doesn’t sound right, does it? No. And the Subject pronoun, Who, should be the Object pronoun, Whom. You is the Subject which gets the Who.
#2. “He gave the book to who I don’t know.” Which is the Subject and which is the Object?
#3. I is the Subject, not That or woman. “I was talking to who that woman was?” -the Object.
#4.“You got that from who?” You is the Subject, for Who, not the Object from Whom received.
#5. “He sold the car to who?” He is the Subject, for Who. The Receiver of action is Whom.
#6. “I (Subject) got the information from Who (Object).” No way. The Object takes Whom. “That is the person I got the information from who that person is?” No way. I, the Subject, takes the pronoun, Who. From where I got the information, that person gets the pronoun. Whom. Reverse the syntax to realize the correct Subject, Object form. “The critic of faulty pronoun use was him.” No. Would you say, “Him was the critic?” Or, “That was the critic who I criticized for faulty pronoun use.” No. I (Subject) takes the pronoun, who. The critic (Object) takes the pronoun, whom. “That was the critic of whom I write.” That’s Good English, formal or casual.