Because, but, so, when and if in Japanese
Japanese links ideas by attaching words to clauses, so the order does not always match English. With から, put the reason before the action or result; だから introduces a result after a complete sentence. For contrast, attach けど to the first clause, keeping だ after nouns and な-adjectives, as in 仕事だけど and 好きだけど. All the example sentences here use casual speech, suitable for friends and family.
Five ways to link everyday ideas
Put the reason first with から
理由から、その理由で起こること・すること。
- informal
明日は朝早いから、もう寝るね。
- informal
彼女は職場の近くに住んでるから、歩いて通ってる。
Add a contrasting idea with けど
前の内容（普通形、名詞・ナ形容詞には「だ」を付ける）けど、対照的な内容。
- informal
この車、好きだけど高いね。
- informal
彼は土曜日は仕事だけど、日曜日は暇だよ。
Introduce the result with だから
原因となる文。だから結果となる文。
- informal
寒いね。だから今日は家にいるよ。
- informal
牛乳がないね。だからちょっと買いに行ってくる。
Say when an action happens with 時に
動作を表す普通形時に、その時にすること。
- informal
朝起きた時に、たいていシャワーを浴びる。
- informal
家に帰った時に、お皿を洗うね。
Say what you will do in that case with なら
条件（名詞または普通形）なら、その場合にすること。
- informal
時間があるなら、散歩に行くよ。
いつ asks “when”; 時 links actions
English uses “when” for both a question and a time link, but Japanese uses different words. The question word you already know is いつ: “いつ行きたい？” asks “When do you want to go?”
To link actions, put a plain verb form before 時, read とき, as in “朝起きた時に、たいていシャワーを浴びる。” 時 means “time”, and に marks that time as when the other action happens. These examples are casual; with people you do not know well or in formal situations, use polite sentence endings such as ます, or end the question with ですか.
- informal
朝起きた時に、たいていシャワーを浴びる。
- informal
いつ行きたい？
Action order with 時 and conditions with なら
In “家に帰った時に、お皿を洗うね。”, 帰った presents arriving home as completed before the dishwashing, even though both actions are still in the future. Before 時, the choice between a plain nonpast form and a た-form depends on the action’s timing, so do not read every た-form as past time from now. The final 洗う can express a future action without an equivalent of English “will”.
“時間があるなら、散歩に行くよ。” means that if having time is the case, the speaker will go for a walk. なら takes a situation as a premise for a decision or response; it is not a replacement for every English “if”. After a noun, attach なら directly without だ, and remember that the casual sentence endings ね and よ here add a conversational tone rather than marking future tense.
- informal
家に帰った時に、お皿を洗うね。
- informal
時間があるなら、散歩に行くよ。