"Он сражался как самурай" - should I put a comma?

Question

Let us consider the following two phrases:

(1) Он сражался, как самурай. (He fought like a samurai.)

(2) Он сражался, не как самурай. (He fought unlike a samurai.)

I am confused as to whether I should put the comma in these sentences.

On the one hand, what I remember from my classes is that I should, although I am unsure whether my understanding is right; I also just found the relevant grammar rule in the Internet, and the rule together with the accompanying examples appears to say that the comma is needed:

Запятая перед словом «как» ставится в случае, .... eсли речь идет о сравнении.

(3) Ее кожа была бела, как алебастр.

(4) Она была прекрасна, как роза.

(5) Он был богат, как Крез.

(Source)

(The numbers 3-5 are added by me as I will refer to these examples later in this post.)

On the other hand, I see in Google that the comma in such sentences is usually or at least very often omitted even in newspapers such as Московский Комсомолец. Below are five random examples from that newspaper:

(6) И сказать себе: “Господи, а я бы на его месте поступил как последняя сволочь”. (Source)

(7) Более того - он поступил как настоящий мужчина и не отказался от своего слова, хотя на него оказывалось колоссальное давление. (Source)

(8) Он поступил как настоящий герой. (Source)

(9) Ну не по-мужски это просто, он поступил как бабушка на скамеечке. Если бы я была мужиком, то дала бы ему в морду! (Source)

(10) Я его уважаю как футболиста, по-человечески тоже нормально относился. Но он поступил как предатель. (Source)

But I also found analogous sentences but with a comma in the very same newspaper! Below are three random examples:

(11) Грипп поступил, как свинья. (Source)

(12) Я поступил, как современный непрофессиональный журналист: не проверил полученные сведения. (Source)

(13) Да, я поступил, как любой нормальный человек, осознавший угрозу для жизни своих близких. (Source)

My impression is that the comma is more often omitted than not, and I also see in Google that the following phrase is almost always written without a comma:

(14) Он поступил как мудак. (He acted like an a##hole.)

In English, I put a comma in phrases like "he acted like an a##hole" if what I want to say is that he acted and that, as an additional remark, the mere fact that he acted makes him comparable to an a##hole. If I want to say that what makes him an a##hole is HOW he acted, not just that he acted, then I do not put a comma.

But this logic does not explain all Russian examples provided above, although I noticed that Sentences (3)-(5) can be terminated before the comma, which might explain its presence. But Sentences (11)-(13) cannot be terminated before the comma, yet the comma is there. I am so much confused.

Anyway, Russian is not English, so the English rules are a wrong lighthouse in the sea mist of subtleties of the Russian language. Only native Russian speakers can help me navigate in that mist. I am humbly asking for your help.

My question is this: What is the principle for making punctuation choices in sentences like Examples (1)-(14)? I would also be very grateful for direct yes or no answers of yours whether you would put a comma in Examples (1)-(14).

As the usage of the comma in such sentences in Московский Комсомолец seems highly inconsistent to me, I would also be thankful for an explanation why one and the same newspaper makes different punctuation choices in apparently analogous sentences.

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UPDATE 1. @Quassnoi suggested that Московский Комсомолец is yellow press, but I just checked and found that even one of the most serious Russian newspapers, Коммерсант, makes inconsistent punctuation choices in "поступил как." Have a look.

UPDATE 2. @БаянКупи-ка provided a link to the relevant grammar rule on gramota.ru, but the rule seems highly confusing and illogical. For instance, it gives the following two apparently contradicting examples:

Ее голос звенел, как самый маленький колокольчик.

Tропинка извивалась как змея.

The provided explanation why the comma is needed in the first sentence and not needed in the second one seems very vague and illogical and is beyond my understanding, and I am unsure whether that grammar source is the ultimate truth.

Answer 1

You can use this source for reference (§ 42.4):

Знаки препинания при оборотах, не являющихся придаточной частью сложноподчиненного предложения (Орфограммка.ру)

1) Сражался(,) как самурай.

Two different meanings are possible:

• he was as good as a samurai at his fighting (comma; usual comparative clause)
• his fighting was worth his samurai status (or 'being a samurai, he took part in that fight' - no comma)

Compare it with examples from that reference source:

Он умер, как настоящий герой («подобно герою»). — Он умер как настоящий герой («умер героем»).

Examples 3) - 5) are correct (usual comparative clauses - with comma).

Examples 6) - 10) and 14) are correct (no comma), see § 42.4, 4) ... оборот образует именную часть составного сказуемого или по смыслу тесно связан со сказуемым...

For that very reason, examples 11) - 13) are wrong. The verb поступил doesn't have it's own finished meaning in the context suggested and only works as a part of a compound predicate.

Answer 2

#1

(1) Он сражался, как самурай. (He fought like a samurai.)
(2) Он сражался, не как самурай. (He fought unlike a samurai.)

In Russian language comma for [как] is a tool to separate two different meanings and you as authour of your sentence must make a decision.

1) Put comma, when you mean [like something/somebody]
2) Do not put comma, whem you mean [as someting/somebody]

He fought, like samurai. -> must be comma separated
He fought as samurai. -> must not be comma separated

[He fought, like samurai] means he is not samurai, but the way he moves look the same as these movements we see at other samurais.

[He fought as samurai] means he was assigned new status - from now he is samurai. And even if his skills is not like samurai (or not enough for true samurai), he is anyway samurai. He was assigned a status of samurai by other samurais.

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Let's make funny example.

I teach you, like a teacher. - that is true.
I teach you as a teacher. - that is a lie.

I am not your teacher, and therefore, I can not teach you as a teacher.
But I can teach you like a teacher, cause I know how teachers usually teach.

So, in Russian it is like this.

Я учу вас, как учитель. - comma must be, The statement is true to reality.
Я учу вас как учитель. - comma must not be. The statement is false to reality.

#2

Ее голос звенел, как самый маленький колокольчик.
Her voice sounded, like the smalest bell.

Comma must be, because it is [like]-case, not [as]-case.

Tропинка извивалась как змея.
The road was curving as if a snake.

[as if]-case is more close to [as]-case.

When you meet cases like this, follow 2 steps.

Step 1. Treat it as [like]-case and mentaly put comma.

Tропинка извивалась, как змея.
The road was curving like a snake.

Step 2. Can I really turn it to [as if]-case by finding the instrumental form for the noun after like.

In our example, can you find the instrumental case for word snake?
Yes, you can.

Tропинка извивалась [змеёй, по-змеиному, как змея].
The road was curving [by snake, snaky, as if a snake].

If you've found the instrumental form, than comma can be skipped.
But still it is [like]-case, cause we compare road curving to snake's curving.
Snake is metaphor.
It is [like]-case without comma.
It is not [as]-case.

Let's try this tool for samurai.

Он сражался [самураем, по-самурайски, как самурай].
He fought [by samurai, samuraily, as if a samurai].

If you as author of the sentence realy mean [Он сражался самураем], then you have a right to skip comma for [like]-case [Он сражался как самурай].

In total. Comma before [как] depends on the meaning you want to express as author.

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Answer to question why [по-учительски] does not give right to skip comma.

When you are in situation to put or not to put, just build both variants in your head and then just check what variant fits to what you mean.

Yes, you are right, that we can find [по-учительски], but this word in Russian language mean [as a teacher] not [like teacher].

[по-учительски] has the same tone as [по-отцовски] = [as father] and [по-приятельски] = [as friend].

But for [по-змеиному] = [like a snake] not [as a snake].

When we say [road like snake] we can allow ourselves to skip comma, because there is no meaning for [road as snake].
Or simply speaking, because option without comma is free from meaning.

We can not skip comma in [teach like teacher] because [teach as teacher] is not free and it has its meaning.

Just let us act according the to the rule.
We've found [по-учительски] and think that it gives us a right to skip comma.
Ok, we skip it.
What do we get?
Я учу вас как учитель.
But what this sentence mean in Russian?
It mas meaning [I teach you as a teacher].
Wow, but I wanted to say, that [like a teacher] not [as a teacher].
What should I do to say [like a teacher]?
Yes, I just have to put comma.
Я учу вас, как учитель.
Now it is [I teach you like a teacher.]

Summary

1) Deside what is your meaning [like ...] or [as ...].
2) If your meaning is [as ...] skip comma, do not put it.
3) If your meaning is [like...] mentaly put comma, but
4) Check if there is meaning for this sentence without comma.
5) If there is meaning and this meaning is [as...] (form is occupied with meaning) then you do not have oppotunity to skip comma for [like...] even if you want.
6) If there is no meaning for sentence without comma and you can find meaninful word [по-...ки][по-...му] (по-учительски, по-змеиному, по-самурайски, по-Митсукосански) than you can skip comma.

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Bonus track

Я задаю вопросы, как Митсуко-сан.
[I ask questions like Mitsuko-san]
I ask questions in style of Mitsuko-san because I like her style.

Я задаю вопросы как Митсуко-сан.
[I ask questions as Mitsuko-san]
1) I ask questions from Mitsuko-san account, beacuse I hacked it and found her login and password and I ask questions, but everybody think that it is Mitsuko-san.
2) There is the second meaning for this option: Mitsuko-san gave me attorney to speak from her voice, that is to be her official representative, and therefore [I ask question as Mitsuko-san] = [Я задаю вопросы как Митсуко-сан] = [I ask question as if I am really Mitsuko-san].

I can build word [по-Митсукосански = по-змеиному, Митсукосанкой = земеёй].

But this does not give me right to skip comma for [like]-case, because form whtout comma is already occupied with meaning and it means to represent Mitsuko-san, which is [as]-case, not [like]-case.

Answer 3

Rule of thumb in such cases (before "как"): if you can ommit everything after comma and what is left still makes sense - it is better to put comma. Otherwise - no comma needed.

Examples:

Он поступил как дурак

"Он поступил " ("he did" ) - has little sense - no comma needed

(About enrollee) "Он поступил, как лучший ученик"

"Он поступил" ("he entered (university)") has sense - comma is desirable

What makes sense and what don't - depends on context and often is up to author