How to list reasons and causes with 「～し」

1. Core Function of 「～し」

「～し」 is a conjunction in Japanese commonly used to enumerate or list reasons, causes, or other related points. Its main functions include:

(1) Enumerating reasons or causes

• It is used to explain a result by listing one or more reasons.
• Example:
  • この店は安いし、品揃えもいいです。
    (This store is cheap, and it also has a good selection.)

(2) Enumerating facts

• It is used to list multiple facts, describing several attributes of something.
• Example:
  • あの人は優しいし、かっこいいです。
    (That person is kind and handsome.)

(3) Adding supplementary information

• It indicates “besides that, also…” with a tone of adding new points.
• Example:
  • 雨も降っているし、風も強いです。
    (It’s raining, and it’s windy too.)

(4) Softening the tone

• When listing only one reason, 「～し」 can imply that there are additional, unspoken reasons, making the statement softer and less direct.
• Example:
  • 忙しいし、今日は行けません。
    (I’m busy, so I can’t go today. – Implying there might be other reasons as well.)

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2. Conjugation Rules

「～し」 can follow verbs, adjectives, and nouns. The conjugation rules depend on the word type:

Word Type	Conjugation	Example
Verb	Plain form + し	疲れるし (I’m tired…)
い-adjective	Plain form + し	楽しいし (It’s fun…)
な-adjective	Root + だ + し	きれいだし (It’s pretty…)
Noun	Noun + だ + し	学生だし (He’s a student…)

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3. Usage Scenarios

(1) Listing multiple reasons

• Used to explain a result by listing several reasons.
• Example:
  • 道が混んでいるし、電車も遅れたし、遅刻しました。
    (The road was congested, the train was delayed, so I was late.)

(2) Listing multiple advantages

• Used to describe several positive attributes of something.
• Example:
  • このカフェは静かだし、コーヒーも美味しいし、よく来ます。
    (This café is quiet, the coffee is good, so I come here often.)

(3) Adding supplementary information

• Adds further context or information about the subject.
• Example:
  • あのレストランは高いし、サービスもよくないです。
    (That restaurant is expensive, and the service isn’t good either.)

(4) Implying other reasons

• Used to list one reason while implying there are additional unspoken reasons.
• Example:
  • 眠いし、今日は早く帰ります。
    (I’m sleepy, so I’ll go home early today. – Implying other reasons exist.)

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4. Comparison with Other Conjunctions

(1) Comparison with 「から」

• 「から」 is more direct, emphasizing a clear cause-and-effect relationship.
• Example:
  • 雨が降ったから、試合が中止になりました。
    (Because it rained, the game was canceled. – Strong cause-and-effect.)
• 「～し」 is softer, often used to enumerate or hint at multiple reasons.
• Example:
  • 雨が降っているし、今日はやめましょう。
    (It’s raining, so let’s call it off today. – Enumerates reasons or hints at others.)

(2) Comparison with 「て」

• 「て」 connects actions or states with a sense of continuity or simultaneity.
• Example:
  • 雨が降って、風が強いです。
    (It’s raining, and it’s windy. – Describes two simultaneous states.)
• 「～し」 has more logical context and is suitable for listing reasons or additional information.
• Example:
  • 雨も降っているし、風も強いです。
    (It’s raining, and it’s also windy. – Emphasizes added information.)

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5. Common Mistakes

(1) Incorrect Conjugation

• For nouns and な-adjectives, 「だ」 must be used before 「し」.
  • Incorrect: きれいし, 学生し
  • Correct: きれいだし, 学生だし

(2) Overuse

• While 「～し」 is useful for listing, excessive use can make a sentence unnecessarily lengthy or repetitive. Focus on key points.

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6. Example Sentences

1. Enumerating Reasons:
   • 明日は忙しいし、天気も悪いし、外出しません。
     (I’ll be busy tomorrow, the weather will also be bad, so I’m staying home.)
2. Enumerating Advantages:
   • あの人は親切だし、頭もいいし、みんなに好かれています。
     (That person is kind, smart, and liked by everyone.)
3. Adding Context:
   • この店は安いし、美味しいです。
     (This store is cheap, and the food is good.)
4. Implying Other Reasons:
   • 時間がないし、明日にしましょう。
     (There’s no time, so let’s do it tomorrow.)

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7. Summary

• Core Uses of 「～し」:
  1. Listing reasons or causes.
  2. Enumerating features or attributes.
  3. Adding supplementary information.
  4. Implying unspoken reasons.
• Conjugation: Verbs and adjectives use plain forms, while nouns and な-adjectives require 「だ」 + し.
• Tone: Softer and more conversational, making it suitable for casual or informal contexts.