This grammar is used to express the cause or reason for something.

It connects two clauses where the first part gives the reason, and the second part shows the result.

This pattern is often used to explain, apologize, or describe a situation.

Commonly used in situations like:

– 道[みち]が　混[こん]でいて、遅[おく]れました。

– 病気[びょうき]で、会社[かいしゃ]を　休[やす]みました。

– 体[からだ]の　具合[ぐあい]が　悪[わる]くて、行[い]けませんでした。

それで is a conjunction used to show a cause-effect relationship between two sentences.

S1 explains the reason or cause, and S2 shows the result or consequence.

Commonly used in everyday conversation to explain why something happened or what action follows from a situation.

This expression is used to ask for permission to do something.

It connects to the テ-form of a verb.

Common responses granting permission include:

・どうぞ (Sure.)

・わかりました (All right.)

・いいです(よ) (Certainly.)

This is a more polite version of V-ても いいですか？

～ですか？ is softened to ～でしょうか？ to sound more respectful and less direct.

Commonly used when making a polite request, especially to a superior or someone you don’t know well.

Used to express obligation or necessity, regardless of intention or desire.

The plain style is ～なければ ならない.

Often used with ～んです (～なければ ならないんです) when explaining reasons.

Example of conjugation:

行[い]く → 行[い]かない → 行[い]かなければ なりません (I have to go)

Used to explain a situation or reason to the listener.

Unlike ～んですが… (which seeks a response), ～んです ends with a statement and is often used to provide background information.

Commonly used when giving reasons for absence, leaving early, or other situations.