Мой брат думает то же, что и я.

My brother thinks the same as I do.

Breakdown of Мой брат думает то же, что и я.

• я: I
• мой: my
• и: and
• брат: the brother
• что: that
• думать: to think
• то же: the same

Questions & Answers about Мой брат думает то же, что и я.

Why is it то же (two words) and not тоже (one word)?

То же and тоже mean different things, even though they sound the same.

• То же (two words) literally means that same (thing) / the same.
  
  • то = that (thing)
  • же = a particle reinforcing identity: the very same
    In this sentence it means the same (thing) that I think.
• Тоже (one word) means also / too / as well.

So Мой брат думает то же, что и я = My brother thinks the same (thing) as I (do).
If you used тоже, it would mean My brother also thinks… and the rest of the sentence would no longer make sense.

What does то же, что и я literally mean?

Broken down literally:

• то – that (thing)
• же – reinforces identity: that very, the same
• что – here: what / which
• и – and, but in this structure: as well, too, just like
• я – I

So literally: He thinks that same (thing), which I (do) as well.
A more natural English rendering: He thinks the same as I do or He thinks the same thing I do.

What exactly is же doing in то же? Can I just say то, что и я?

In то же the же is a particle that strengthens the idea of exact identity: that very same (thing).

• то, что и я – grammatically possible, but it sounds incomplete or less natural here.
• то же, что и я – is the standard, idiomatic pattern meaning the same (thing) as I (do).

You will very often see то же in this kind of comparison of identity, often interchangeable with то же самое (exactly the same thing).

Why is there a comma before что: то же, что и я?

Russian normally separates a main clause and a subordinate clause with a comma.

• Мой брат думает то же – main clause: My brother thinks the same (thing).
• что и я (думаю) – subordinate clause specifying what that same thing is.

Because что и я introduces a subordinate clause (even though the verb думаю is omitted), Russian punctuation requires a comma:
…думает то же, что и я.

Why is it я and not меня in что и я?

Think of the full, non‑elliptical version:

• Мой брат думает то же, что и я думаю.
  – My brother thinks the same (thing) that I think.

Here я is the subject of the omitted verb думаю, so it must be in the nominative case.
Using меня would correspond to something like что меня (what me), which is ungrammatical in this context.

What is the purpose of и in что и я? Could we say что я instead?

The и here reinforces the idea of parallelism: …that I do as well / too / just like I do.

• то же, что и я – very natural, strongly highlights the same as I (do).
• то же, что я – grammatically correct, but less idiomatic and a bit drier; Russians usually prefer что и я here.

So и is not strictly required by grammar, but it is strongly preferred in this comparison pattern.

Can I say Мой брат думает так же, как я instead? Is there a difference?

Yes, you can, and it is very natural.

• думает то же, что и я – focuses on the content: He thinks the same thing / has the same opinion as I do.
• думает так же, как я – focuses on the way / manner: He thinks in the same way as I do.

In many real contexts (opinions, views) these two are effectively interchangeable, but grammatically the first talks about the same object of thought, the second about the same way of thinking.

Is Мой брат думает как я correct? How is it different from думает то же, что и я?

Мой брат думает как я is correct, but it means something a bit different:

• думает как я – He thinks like me, i.e. he has a similar mentality, approach, or way of reasoning, but not necessarily the very same opinion on this particular issue.
• думает то же, что и я – He thinks the same (thing) as I do, i.e. we share the same specific opinion or idea.

So if you mean same opinion about something concrete, use то же, что и я (or так же, как я).

Can I repeat the verb and say Мой брат думает то же, что и я думаю?

Yes, that is grammatically correct:

• Мой брат думает то же, что и я думаю.

However, in natural Russian this repetition of думает / думаю sounds redundant. It is much more idiomatic to omit the second verb and say:

• Мой брат думает то же, что и я.

Russians often drop a repeated verb in the second part of such comparisons.

Is there a difference between то же and то же самое in this sentence?

You could say:

• Мой брат думает то же, что и я.
• Мой брат думает то же самое, что и я.

Both are correct and mean essentially the same: He thinks the same (thing) as I do.
То же самое is a bit more emphatic: exactly the same thing, but in everyday speech the difference is very small here.

How does Мой брат думает то же, что и я differ from Мой брат тоже так думает?

They highlight different things:

• Мой брат думает то же, что и я.
  – Direct comparison of contents: He thinks the same (thing) as I (do).
• Мой брат тоже так думает.
  – Uses тоже = also. It means: My brother also thinks so, in addition to someone already mentioned.

So то же compares what he thinks to what I think.
Тоже compares him to other people (including me) who think this way.

Why is брат in the nominative (мой брат) and not in some other case?

In this sentence мой брат is simply the subject of the verb думает:

• Кто думает? – (Мой) брат.

Subjects in Russian take the nominative case, so мой брат must be nominative.
Other cases (e.g. моего брата) would be used only if brother had another role, such as an object or a possessor, which is not the case here.