Learn Hardcore Japanese: sensei ha siken no pointo wo setumeisimasita. - The teacher explained the key points of the exam.

You could say 先生が試験のポイントを説明しました, which is grammatically fine, but it feels more like you’re emphasizing which person explained it (e.g., “It was the teacher who explained the points,” as opposed to someone else).

In a neutral context where “the teacher” is just the topic, 先生は is more natural.

What does 試験のポイント literally mean, and what is の doing here?

試験のポイント literally means “the points of the exam” or “the important points for the exam.”

試験 (しけん) = exam, test
の = possessive/connecting particle, similar to “of” or English ’s
ポイント = points / key points

So 試験のポイント works like:

試験のポイント → exam ’s points → the main points of the exam

What exactly does ポイント mean here? Why use a katakana word instead of a native Japanese word?

ポイント (pointo) here means “important points / key points / main ideas.”

You could also say:

試験の要点 (ようてん) – main points of the exam
試験の大事なところ – the important parts of the exam

But ポイント is very common in everyday speech and in school contexts. Katakana loanwords often sound a bit casual, modern, or easy to grasp, so teachers frequently say things like:

この問題のポイントはここです。 – The key point of this question is here.
試験のポイントをまとめましょう。 – Let’s summarize the exam points.

So it’s natural, not strange, to use the English-derived ポイント here.

What is the function of を after ポイント?

を marks ポイント as the direct object of the verb 説明しました (“explained”).

試験のポイントを説明しました
→ (Someone) explained the points of the exam.

Pattern:
[Object] を [Verb]

本を読みます – I read a book.
日本語を勉強します – I study Japanese.
ポイントを説明しました – (He/She) explained the points.

Why is the verb 説明しました at the very end of the sentence?

Japanese is basically an SOV (Subject–Object–Verb) language. The verb normally comes last in neutral sentences:

(Topic/Subject) – (Objects / details) – Verb

So:

先生は – topic/subject (“the teacher”)
試験のポイントを – object (“the exam points”)
説明しました – verb (“explained”)

Putting the verb at the end is normal and expected in Japanese, unlike English where the verb comes earlier.

Can I change the word order, for example: 試験のポイントを先生は説明しました?

Yes. Japanese word order is relatively flexible, as long as the particles stay attached to the right words.

先生は試験のポイントを説明しました。
試験のポイントを先生は説明しました。

Both are grammatically correct. The second one puts a bit more focus on 試験のポイント (what was explained), while the first feels more neutral and common in textbooks. In spoken Japanese the difference is usually small; context and intonation add nuance.

What is the difference between 説明しました and forms like 説明する or 説明します?

All of these come from the verb 説明する (せつめいする) – “to explain.” It’s a suru-verb (noun + する).

Key forms:

説明する – dictionary/plain non-past
- “to explain / explains / will explain” (depends on context)
説明します – polite non-past
- “explain / will explain” (polite)
説明した – plain past
- “explained”
説明しました – polite past
- “explained” (polite) ← used in your sentence

So 説明しました is simply the polite past tense: “(someone) explained.”

Does 説明しました always mean past tense? How would I say “The teacher will explain the exam points”?

Yes, 説明しました is clearly past tense: “explained.”

To say “will explain” (or sometimes “explains” in a general/future sense), you use the non-past polite form:

先生は試験のポイントを説明します。
→ “The teacher will explain the points of the exam.” / “The teacher explains the exam points.”

Japanese non-past (します) often covers both present and future, so context decides whether it sounds like “explains” or “will explain.”

What does 試験 mean exactly? Is it the same as テスト?

試験 (しけん) and テスト (tesuto) both mean “test / exam,” but there’s a nuance:

試験 – a bit more formal/serious; often used for official exams, school exams, entrance exams, qualifications, etc.
- 入学試験 – entrance exam
- 期末試験 – final exam
テスト – can be more casual and is used broadly for tests, quizzes, check-ups, etc.
- 小テスト – quiz

In many school situations, they can overlap, and which one is used may depend on the school or teacher’s style. In your sentence, 試験のポイント sounds natural for “exam points.”

Does 先生 mean “the teacher,” “a teacher,” or “my teacher”? There’s no article like “the” or “a.”

Japanese doesn’t have articles like “a” or “the.” The exact meaning of 先生 depends on context:

Could be “the teacher” (a specific teacher everyone already knows about)
Could be “my teacher / our teacher”
Could be “a teacher” (some teacher, when context is unclear)

In an actual conversation, the listener would use the surrounding context to decide. In English translation, we usually pick “the teacher” here because it sounds most natural.

Can words like 先生, は, or を be dropped in casual speech?

Sometimes, yes—especially when the meaning is clear from context.

For example, if it’s already obvious you’re talking about the teacher:

（先生は）試験のポイントを説明しました。
→ You can drop 先生は and just say:
試験のポイントを説明しました。 – “(They) explained the exam points.”

Particles like は and を are often not dropped in writing or careful speech, but:

In very casual speech, especially with friends, some particles may be omitted:
- 試験のポイント説明した。 (dropping を) – casual, but can sound a bit rough or telegraphic.

For learners, it’s better to keep the particles until you’re very comfortable with them.

How do you pronounce each part of the sentence?

Here’s the sentence with readings and rough romaji:

先生 – せんせい (sensei)
は – pronounced わ (wa) when used as the topic particle
試験 – しけん (shiken)
の – の (no)
ポイント – ぽいんと (pointo)
を – pronounced お (o) as the object particle
説明しました – せつめいしました (setsumei shimashita)

Full reading:
先生は試験のポイントを説明しました。
→ Sensei wa shiken no pointo o setsumei shimashita.

Could I say 試験のポイントについて説明しました instead? What’s the difference?

Yes, you can say:

先生は試験のポイントについて説明しました。

Here:

について = “about / regarding”

Nuance:

試験のポイントを説明しました。
→ “(The teacher) explained the exam points.”
(The points themselves are the direct object being explained.)
試験のポイントについて説明しました。
→ “(The teacher) explained about the exam points.”
(Focus is on the topic of the explanation.)

The difference is subtle; both are natural. The original with を is a bit more straightforward and common in textbooks.