Learn Hardcore Japanese: sore nara watasi mo wakaru to omoimasu. - If that's the case, I think I understand too.

それは: just “that (as for that) …”
- Example: それは難しいです。 – “That is difficult.”
それだったら: very close in meaning to それなら, a bit more colloquial and often a bit more “spoken-feeling”.
- Example: それだったら、私も行きます。 – “If that’s the case, I’ll go too.”

In many everyday contexts, それなら and それだったら can both be translated as “in that case” or “then,” with only a small nuance difference in style/register.

In this sentence, is それ the thing that I “understand” in 分る?

Not directly.

Here, それ is inside the phrase それなら, which is functioning as a conditional frame:

それなら = “if that’s the case / in that case”

It does not directly serve as the grammatical object of 分る. The thing that is “understood” is coming from the larger conversation context (something just explained or discussed), and is not explicitly repeated.

So the structure is more like:

それなら, (私は) (それが) 分ると 思います
- “If that’s so, I think (I) understand (that).”

The それ you see is about setting the condition (“if that…”), not about explicitly marking the thing you understand.

Why is 私 (I) included here? Could it be omitted?

Yes, 私 can be omitted, and it often is in natural Japanese.

With 私:
- それなら私も分ると思います。
- “In that case, I think I understand too.”
Without 私:
- それなら分ると思います。
- “In that case, I think I understand.” (Still clearly “I” from context.)

私 is used here to emphasize that I, as opposed to someone else, also understand. Adding も to 私 (“I too”) reinforces that contrast: other people (or someone mentioned before) understand, and now “I do too.”

What does the particle も after 私 do here?

も means “also / too / as well.”

In 私も分ると思います, it tells you that:

Someone else (or some other situation) has been mentioned as understanding,
and I am included in that group too.

So the nuance is:

“If that’s the case, I also think I understand.”
Implied: “Others understand (or will understand), and I’m one of them too.”

Why is there no particle like は or が after 私も?

私も here already functions as the subject-like element.

私 = “I”
も replaces what would normally be は or が in many cases, adding the meaning “also / too.”

You could think of it this way:

私は分る → “I understand.”
私も分る → “I also understand.”

You don’t say 私もが分る or 私もは分る; も is the only particle attached to 私 here and covers the subject-marking role in this sentence.

What does the と between 分る and 思います mean?

Here と is the quotative particle. It marks the content of what is thought or said. The pattern is:

[sentence in plain/dictionary form] + と + 思います
→ “I think (that) [sentence].”

So in:

分ると 思います

the と is like the English “that” in:

“I think that I understand.”

It tells us that 分る is the thing being thought.

Why is it 分ると思います and not 分りますと思います?

Verbs before と思います must be in their plain (dictionary) form, not the polite ます form.

Pattern:

分かる (plain) → 分かると思います
行く (plain) → 行くと思います
高い (adjective, plain) → 高いと思います

You cannot say:

✗ 分りますと思います
✗ 行きますと思います

The 思います at the end is what carries the politeness. The embedded clause (分る) stays in plain form even in polite speech:

Polite: 分かると思います。
Casual: 分かると思う。

Why is it written 分る and not 分かる? Are they different?

They are the same verb, pronounced the same way (わかる) and meaning “to understand / to be clear (to someone).”

分かる – modern standard spelling (most common in textbooks, modern writing).
分る – an older or alternative spelling that you still sometimes see, especially in certain styles or with some publishers/writers.

For learning purposes, you should treat 分かる as the normal form and read both 分かる and 分る as わかる.

Who is doing the thinking in 思います if there is no subject like “I”?

In Japanese, the subject “I” is often omitted when it’s obvious from context.

With 思います, unless context clearly indicates otherwise, the default subject is the speaker:

思います → “I think.”
そう思います → “I think so.”
分かると思います → “I think (I) understand.”

If the subject were someone else, that would usually be specified:

彼は分かると思います。 – “I think he understands.”
田中さんはそう思っています。 – “Mr. Tanaka thinks so.”

What’s the nuance difference between 私も分かります and 私も分かると思います?

私も分かります

More direct: “I understand too.”
Sounds more confident and straightforward.

私も分かると思います

More tentative or modest: “I think I understand too.”
Softens the claim, leaving room for the possibility that you might be mistaken.
Often feels more polite/indirect, especially in formal or careful speech.

So 分かると思います is a good choice when you don’t want to sound too blunt or overly sure of yourself.

Does 分かる mean “to know” or “to understand”? Is it transitive or intransitive?

分かる (わかる) primarily means “to be understood / to be clear / to become understood”, but it’s usually translated as “to understand” in English.

Grammatically, it’s intransitive:

私に 日本語が 分かる。
- Literally: “Japanese is understandable to me.”
- Naturally: “I understand Japanese.”

In everyday speech, learners and teachers often treat it as “to understand,” but the underlying structure is:

[person] に
- [thing] が
  - 分かる
    - “The thing is clear to the person.”

In your sentence, those parts are omitted because they’re understood from context.

Can I change the word order to それなら、分かると私も思います?

You can, and it’s grammatically possible, but it sounds less natural and more marked.

The usual, natural order is:

それなら私も分かると思います。

This order:

Sets the condition (それなら),
Introduces the subject-like element (私も),
Gives the content of the thought (分かる),
Then the thinking verb (思います).

Japanese word order is relatively flexible, but moving 私も after 分かると draws unusual emphasis and can feel stiff or literary. For normal conversation, stick with the original order.