kare no kurou wo rikaisita.

の links two nouns and shows a relationship between them. Here, it works like his in English.

• 彼 = he / him / boyfriend depending on context
• 彼の = his
• 苦労 = hardships / struggles / difficulties

So 彼の苦労 means his hardships or the struggles he went through.

を marks the direct object of the verb, meaning the thing being understood.

In this sentence:

• 彼の苦労 = what is being understood
• 理解した = understood

So 彼の苦労を理解した literally means understood his hardships.

理解した is the plain past form of 理解する, which means to understand.

• 理解する = understand
• 理解した = understood

So the sentence is in the past tense: someone understood his hardships.

Depending on context, English might also translate it as came to understand.

Japanese often leaves out the subject when it is clear from context.

So 彼の苦労を理解した。 does not explicitly say I, she, they, and so on. It simply says:

• [Someone] understood his hardships.

In natural context, the listener is expected to know who did the understanding.

Not always. 彼 can mean:

• he
• him
• sometimes boyfriend, depending on context

In 彼の苦労, it usually means his. If the broader context were about someone's romantic partner, it could also mean my/her boyfriend's hardships, but the most basic reading is his hardships.

苦労 means hardship, trouble, struggle, difficulty, especially the kind someone experiences over time.

It often suggests:

• effort
• suffering
• going through difficult circumstances

So it is stronger and more personal than just a small problem. In this sentence, 彼の苦労 suggests the difficulties he has had to endure or work through.

Because the sentence is focused on the object 彼の苦労 and the subject is omitted.

A full sentence could be something like:

• 私は彼の苦労を理解した。 = I understood his hardships.
• 彼女は彼の苦労を理解した。 = She understood his hardships.

Japanese often drops information that is already understood, so leaving out は or が is very normal.

Yes, but Japanese word order is guided more by particles than by position alone.

Here the structure is:

• 彼の苦労 = noun phrase
• を = object marker
• 理解した = verb

A very literal order is:

• his hardships understood

But natural English becomes:

• [Someone] understood his hardships.

The verb usually comes at the end in Japanese.

They are similar, but not exactly the same.

• 分かった often means got it / understood / realized
• 理解した is more formal and more intellectual, like understood clearly or comprehended

So 彼の苦労を理解した sounds like the speaker truly understood the nature of his struggles, not just that they noticed them.

Yes. Japanese nouns usually do not show singular/plural the way English does.

So 苦労 can mean:

• hardship
• hardships
• struggle
• struggles

English translation depends on context. In many cases, his hardships or his struggles sounds most natural.

Japanese does not use articles like English does.

So 彼の苦労 does not separately say the hardships or his hardships with an article system. The possessive 彼の already makes it specific enough.

That is why Japanese can express the idea without a word corresponding directly to the.

Yes, it can. 彼の苦労 often carries an emotional sense of what someone has gone through. Saying 理解した can imply more than just intellectual understanding—it can suggest empathy or appreciation for his experience.

So depending on context, the sentence may feel like:

• I understood what he had been through.
• I came to appreciate his struggles.

That nuance comes from both 苦労 and the context, not just from the grammar alone.