更(さら)にEven more or further, Again, More and more

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).

その上 and 更に are both relatively formal expressions used at the beginning of a sentence to add information. While often interchangeable, they differ subtly: 更に can imply that the added point is of the same type as what came before, while その上 can highlight that the following point is particularly notable or worthy of emphasis.

Both add information, but differ in nuance. しかも emphasizes reinforcement or surprising addition, as in この料理はおいしい。しかも安い (This dish is delicious. And what’s more, it’s cheap). 更に is more formal, indicating progression or escalation, as in 明日は更に寒くなるでしょう (Tomorrow it will get even colder).

また is common in both speech and writing, meaning 'again' or introducing additional information, like 'moreover' or 'additionally'. 更に is more formal and used in writing or structured speech, with the nuance of 'even more' or 'beyond that', often indicating further change or escalation.

Both 再び and 更に can involve repetition or continuation, but they differ in meaning. 再び means 'again' or 'once more', and is used when something is done a second time after a pause, e.g. '再び会う' ('to meet again'). 更に means 'further' or 'more', and emphasizes intensification or accumulation, e.g. '更に深まる' ('to deepen further').

更に and ますます both suggest addition or progression, but with different nuances. 更に emphasizes adding something on top of what already exists, e.g. '更に三人が参加した' ('Three more people joined'). ますます highlights a state intensifying over time, e.g. 'ますます寒くなってきた' ('It's gotten colder and colder').