上(うえ)にAs well, Besides, In addition to

また and 上に both add information, but differ in usage and tone. また appears at the beginning of a sentence or phrase and means 'moreover' or 'again'. It's common in both speech and writing. 上に follows nouns, verbs, or adjectives and conveys a similar meaning, but with a more formal or written tone.

上に and おまけに both introduce additional information, but differ in tone. 上に is neutral and formal, as in 彼は親切な上に、頭もいい (He is kind, and on top of that, smart). おまけに often emphasizes worsening conditions, as in 雨だった。おまけに風も強かった (It was raining. On top of that, the wind was strong).

上に and 更に both add information, but their nuance differs. 上に connects additive facts or qualities, often with a static or descriptive tone, as in 彼は真面目な上に礼儀正しい (He is serious, and also polite). 更に emphasizes progression or intensification, as in 更に速く走った (He ran even faster).

上に and 上は share the same kanji but serve different grammatical roles. 上に expresses accumulation of traits or actions, as in 忙しい上に風邪もひいた (I’m busy, and on top of that I caught a cold). 上は introduces a conditional or resolved stance, as in 引き受けた上は最後までやる (Since I accepted it, I’ll see it through).

その上 and 上に both convey the idea of in addition, but differ in structure and tone. その上 is a conjunctive adverb used between sentences, as in 彼は遅刻した。その上、宿題も忘れた (He was late. On top of that, he forgot his homework). 上に functions within a sentence to link clauses, and is often used in more structured or descriptive contexts.

上に (literally, 'on top of') can be used as a slightly formal way to express 'in addition to (A), (B)', e.g. 安い上に、美味しい ('In addition to being inexpensive, it's tasty.'). While し～し is similar in that it lists multiple things, it specifically does so in the context of giving reasons for something, e.g. 安いし、美味しいし、一番好きなお店です ('It's inexpensive, it's tasty too, and so it's my favorite shop.').

上 and 上に share the same kanji but serve distinct functions. 上に adds reasons or qualities in a cumulative way, as in 綺麗な上に頭もいい (In addition to being pretty, she’s also smart). 上 by itself expresses viewpoint, as in 法律上の問題 (a problem from a legal standpoint). The former is additive, the latter indicates perspective. Both are relatively formal expressions.

Both use 上 but differ quite a bit in meaning. 上に adds information, like '(B) in addition to (or 'on top of') (A)', typically within the same general category, e.g. 彼は親切な上に頭もいい ('He's smart in addition to being kind.'). In contrast, 上で expresses an action happening after (lit. 'upon') another action or condition being realized, e.g. 社長に相談した上で決めましょう ('Let's decide after consulting the president.').