I don't think the article applies to this idiom.

See for instance https://www.collinsdictionary.com/dictionary/english/by-your...

> by yourself

> PHRASE

> If you do something _by yourself_, you succeed in doing it without anyone helping you.

> "I didn't know if I could raise a child by myself."

I'm afraid I'm not following your point.

My understanding is that "yourself", "myself", etc. are reflexive pronouns. I.e., they're used when and only when referring to the very same person as the sentence's subject.

The examples you mentioned fit that pattern. The message on the computer screen doesn't.

Sentence verb: to be

Who is being by somebody (the subject): you

Who is the subject being by (the object): yourself

The grammar in the original sentence is correct, you're just getting confused about which word is the verb. "Repairable" is not a verb, it is an adjective.

Another way to phrase the same sentence would be "by yourself, you can repair the system". Another phrasing would be "you can repair the system when you are by yourself". You would not say "by you, you can repair the system".

"Repairable by you" is a different, also grammatically correct sentence, with a different meaning. "You can repair it" and "you can repair it on your own" (aka "by yourself") mean two different things.

The subject of "the phone is repairable" is the phone.

If you want to say "I think the phone is repairable by myself" it's grammatical, but strange because people don't usually think with assistance.

subject: I

verb: think

object: the phone is repairable

adverb: by myself

edit: I think I'm agreeing with you, but I couldn't tell what you meant by "the original sentence."

I thought that the article you posted didn't really apply to the phrase "by yourself". The examples quoted there sounded much more grating to me (using "myself" as the subject of a sentence for instance).

I'm certainly not in a position to argue in favor or against the question if "by yourself" could ever be "correct" grammar in the passive voice. An easier question would be whether "you can repair it yourself" sounds cleaner than "it is repairable by yourself". And there I'd certainly agree.

> > "I didn't know if I could raise a child by myself."

I/could/raise (by myself)

Instead try:

"I didn't know if a child could be raised by myself."

Child/could/be (by myself?)

It's the difference between "you could repair (by yourself)" and "phone could be (by yourself.)"

Thanks for sharing... didn't know about reflexive bit. Always good to learn something new ;)

If your point is to critique my comment, then I think it's misplaced.

Note what I wrote:

> If your goal is to use traditionally correct grammar, use "you" rather than "yourself".