Learn Hardcore Japanese: muzukasii bunsyou wo honyakusurutoki, zisyo wo sirabemasu. - When translating difficult sentences, I look things up in a dictionary.

難しい is an i-adjective. I-adjectives can directly attach to nouns without any extra particle. Here, 難しい describes 文章, giving us 難しい文章 = “difficult text(s).”

What is the function of を in 難しい文章を翻訳するとき?

The particle を marks 難しい文章 as the direct object of the verb 翻訳する (“to translate”). It tells us what is being translated.

How does the phrase 翻訳するとき work grammatically, and what does it mean?

翻訳するとき is formed by the dictionary form of the verb 翻訳する + とき (“when”). Together they create a time clause meaning “when (I) translate.” In Japanese, this subordinate clause indicates an action that takes place before or at the same time as the main clause.

Why is 翻訳する in the dictionary form instead of the て-form or past form before とき?

When you attach とき directly to a verb:

Using the dictionary form shows the action happens before or while the main clause.
Using the た-form
- とき would shift the nuance to “after finishing that action.”
The て-form links two actions more like “translate and then…” rather than marking time.

Why is there a comma after とき in 翻訳するとき、辞書を調べます?

The comma separates the subordinate time clause (翻訳するとき) from the main clause (辞書を調べます). It makes the sentence clearer by showing “When I translate difficult texts, (then) I look things up in a dictionary.”

What does 辞書を調べます mean, and could you use で instead of を?

辞書を調べます literally means “examine/look into a dictionary.” Here, を marks 辞書 as the object of 調べる (“to investigate/look up”). You could also say 辞書で調べます, using で to indicate the dictionary as the tool or place:

辞書を調べます = focus on examining the dictionary itself.
辞書で調べます = focus on using the dictionary as a tool for looking something up.

What level of politeness is conveyed by 調べます?

調べます is the -ます form, which is polite (丁寧語). It’s suitable for everyday conversation with people you’re not extremely close to, or for moderately formal writing.

Why is there no subject like 私は in the sentence?

In Japanese, the subject is often omitted when it’s clear from context. Here, it’s understood that “I” (the speaker/translator) is doing the translating and looking things up, so 私は is dropped.