Он пожал плечами и ничего не сказал.

Because the verb пожать / пожимать плечами is a fixed expression meaning to shrug. With this expression, плечами is in the instrumental plural.

So Russian treats it roughly like to move/shake with the shoulders, not to shrug the shoulders in the direct-object sense English uses.

• плечи = shoulders
• плечами = with the shoulders / by means of the shoulders

This is just the normal case pattern for this idiom:

• Он пожал плечами. = He shrugged.
• Она только пожала плечами. = She only shrugged.

Пожал is the masculine past tense singular form of пожать, which is a perfective verb.

In this sentence, пожал плечами means shrugged.

A useful thing to know is that пожать has more than one meaning depending on context:

• пожать руку = to shake someone’s hand
• пожать плечами = to shrug
• пожать can also mean to reap/harvest in other contexts

So here you understand the meaning from the object and idiom:

• пожал плечами = shrugged

Russian normally requires this kind of negative structure. If the verb is negative, words like nothing, nobody, nowhere also usually appear in negative form.

So:

• не сказал = did not say
• ничего = nothing

Together:

• ничего не сказал = said nothing / didn’t say anything

This is completely normal Russian grammar, not an emphatic double negative.

Compare:

• Я ничего не знаю. = I know nothing / I don’t know anything.
• Он никого не видел. = He saw nobody / He didn’t see anybody.

Because the clause is negative: не сказал.

In negative sentences, Russian typically uses negative pronouns:

• ничего = nothing
• никого = nobody
• никогда = never

By contrast:

• что-то = something
• что-нибудь = anything / something, depending on context

So:

• Он ничего не сказал. = He said nothing / He didn’t say anything.
• Он что-то сказал. = He said something.
• Если хочешь, скажи что-нибудь. = If you want, say something / anything.

Because the subject is он = he.

In Russian past tense, verbs agree in gender and number:

• он сказал = he said
• она сказала = she said
• оно сказало = it said
• они сказали = they said

The same thing happens with пожал:

• он пожал
• она пожала
• они пожали

So the masculine ending is there because the subject is masculine singular.

Because the sentence presents two completed, whole actions:

• he shrugged
• he didn’t say anything

Russian often uses the perfective past when describing single completed events in a narrative.

Here:

• пожал comes from пожать — a complete shrug as one action
• сказал comes from сказать — to say, as a complete act

So the sentence sounds like a finished sequence: he shrugged and said nothing.

If you used imperfective forms, the meaning would shift:

• пожимал плечами = was shrugging / used to shrug
• не говорил ничего = was not saying anything / used to say nothing

Those would suggest duration, repetition, or background action rather than a simple completed event.

Yes, often it could.

Russian frequently drops subject pronouns when the subject is clear from context:

• Пожал плечами и ничего не сказал.

That can still mean He shrugged and said nothing, if the context already makes it clear who is being talked about.

However, including он is also perfectly normal. It may:

• make the sentence clearer
• sound slightly more explicit
• help start a new sentence or shift focus back to that person

So both are possible, depending on context.

И simply means and. It links the two actions:

• Он пожал плечами = He shrugged
• и ничего не сказал = and said nothing

This is a very common way to connect actions in Russian narrative.

Sometimes Russian can join ideas without и, but here и is the most natural straightforward choice.

Not necessarily. The most natural English translation is usually just shrugged.

So:

• Он пожал плечами. = He shrugged.

English often does not need his shoulders, because shrug already implies shoulders. Russian, on the other hand, uses the full idiomatic phrase пожать плечами.

So when learning it, it is best to remember:

• пожать плечами = to shrug

Ничего is the genitive singular/neuter form of ничто in this construction.

After many negated verbs, Russian uses forms like:

• ничего = nothing
• никого = nobody

In Он ничего не сказал, ничего is the normal form used with the negated verb не сказал.

For learners, the easiest practical rule is:

• after a negative verb, use ничего for nothing
• after a negative verb, use никого for nobody

You do not need to overanalyze it at first; this pattern is extremely common and worth memorizing as a chunk.

Yes. Russian word order is flexible, though the original sentence is the most neutral.

Original:

• Он пожал плечами и ничего не сказал.

Other possible orders include:

• Он ничего не сказал и пожал плечами.
• Плечами он пожал и ничего не сказал. — possible, but marked or stylistically unusual
• Ничего он не сказал, только пожал плечами. — emphasizes he said nothing

Changing the order usually changes the focus or emphasis, not the basic meaning.

So for a learner, the given version is a very natural standard pattern.

Both are possible, and both mean essentially the same thing.

• ничего не сказал is very common and neutral
• не сказал ничего is also correct, but may sound slightly more emphatic or stylistically shaped depending on context

In many everyday cases, the difference is small:

• Он ничего не сказал.
• Он не сказал ничего.

Both mean He said nothing / He didn’t say anything.

For learners, ничего не сказал is the safest default pattern to remember.

The past tense verbs would change to agree with the subject.

For she:

• Она пожала плечами и ничего не сказала.

For they:

• Они пожали плечами и ничего не сказали.

Notice:

• masculine singular: пожал, сказал
• feminine singular: пожала, сказала
• plural: пожали, сказали

So in Russian, past-tense verb forms give you information about the subject’s gender and number.