し

1. 1Lists two or more reasons or features cumulatively, often leading to a conclusion or judgment.Ex. 1
2. 2Gives one reason as a representative example, often with も, implying other reasons exist.Ex. 2

Common in everyday conversation and casual writing, typically used to justify a decision, invitation or opinion by piling up reasons. から also gives reasons, and several can be listed with it, but it presents them straightforwardly as the cause. し frames reasons as a non-exhaustive list, which softens the statement. It is less formal than additive expressions such as 上に or に加えて.

• からN5「から」 overlaps with 「し」 only when expressing cause: 「から」 states the cause-effect directly, while 「し」 lists reasons and implies there are more, sounding softer. Use 「から」 for a single reason; 「から」 is neutral in register, while 「し」 leans colloquial.
• 上にN2When simply stacking facts in the same direction, you can swap in the more formal 「上に」, but its sentence generally cannot end with an invitation or request, so forms like 「散歩に行こう」 cannot be replaced. It connects as 「静かな上に」 or 「学生の上に」, without adding 「だ」.
• に加えてN3「に加えて」 mainly attaches to nouns (other words need 「の」 or 「こと」 etc.), is used in writing, and objectively adds information without itself expressing a reason; 「し」 attaches to sentences, is colloquial, and lists reasons or items. In formal writing, 「に加えて」 can replace 「し」 when listing reasons.
• ばかりでなくN3「ばかりでなく」 means 'not only... but also...' and resembles 「し」 only when listing items in parallel, but it lacks the sense of listing reasons and leading to a conclusion. Its register is neutral and it works in writing too; な-adjectives take 「な」 rather than 「だ」.
• 〜たり〜たりするN3「〜たり〜たりする」 cites representative actions or states or shows alternation/repetition, usually ending with 「する」, uses the た-form before 「たり」, and is neutral in register; 「し」 lists reasons or items with a following judgment or decision, and is colloquial. The two are generally not interchangeable.
• だの〜だのN2「だの〜だの」 carries a tone of dissatisfaction, often listing others' complaints or excuses, and is frequently followed by 「と言う」; 「し」 has no negative nuance, lists reasons leading to a judgment, decision, or invitation, and can cite just one item. The two are generally not interchangeable.

から presents its reason or reasons directly as the cause without implying others. 上に, に加えて and ばかりでなく add points in a more formal, written style; 〜たり〜たりする lists sample actions rather than reasons, and だの〜だの lists items, often with a complaining tone.