daigaku no kyouju ga kenkyuushitsu de jikken no kekka o setsumeishite kuremashita.

A university professor explained the results of the experiment in the laboratory.

Breakdown of daigaku no kyouju ga kenkyuushitsu de jikken no kekka o setsumeishite kuremashita.

• を: direct object particle
• が: subject particle
• の: possessive case particle
• で: location particle

Questions & Answers about daigaku no kyouju ga kenkyuushitsu de jikken no kekka o setsumeishite kuremashita.

Why is が used after 教授 instead of は?

が marks 大学の教授 as the grammatical subject: the professor is the person who performed the action.

So here:

• 大学の教授が = the university professor did it

If you used は instead, the sentence would feel more like you were introducing the professor as the topic and then saying something about them:

• 大学の教授は研究室で実験の結果を説明してくれました。

That can also be correct, but it has a slightly different feel:

• が = focuses on who did the action
• は = focuses on the professor as the topic

In many basic sentences like this, が is the most straightforward choice.

What does の mean in 大学の教授 and 実験の結果?

の often connects two nouns. It can show possession, belonging, or a close relationship.

In this sentence:

• 大学の教授 = a university professor / professor at a university
• 実験の結果 = the result(s) of the experiment

So の is doing similar work to English of or sometimes an apostrophe-s, but in Japanese it is much more broadly used between nouns.

A helpful way to think about it:

• A の B = B related to A

Examples here:

• 大学の教授 = professor related to a university
• 実験の結果 = results related to an experiment

Why is で used after ?