また

また is an uninflected adverb and conjunction. While the kanji 又(また) exists, modern Japanese guidelines recommend using hiragana for the conjunction. Its meaning shifts depending on context:

1. Repetition ('Again'): When placed before a verb, it indicates the action is repeating. Unlike もう一度（いちど） (one more time), which counts a specific instance, また focuses on the fact that the event is recurring (e.g., 'It's raining again'). It can also carry a nuance of annoyance or surprise when something repeats unexpectedly (e.g., 「またか！」 - 'Again?!').

2. Addition ('Also / In addition / Moreover / Furthermore / Additionally'): When placed at the start of a sentence or between clauses, it adds a new fact. Importantly, また is not used to connect simple nouns like the English 'and', except in the specific pattern of 'Noun + また + Noun' using the same noun to express an endless succession (e.g., 山また山 - mountains upon mountains). In formal writing, it is often followed by a comma (また、〜). It is also used to express simultaneous states or roles, such as in the pattern 〜であり、また〜でもある (is X, and also is Y). Note that また is related to または, which is a formal or written conjunction for 'or' (Choice A or Choice B). In everyday spoken Japanese, 'or' is more commonly expressed using か or それとも. In legal contexts, また is used to mean 'Furthermore' at the start of a sentence, while または is strictly mandated to be written in kanji (又は) for 'or'.

3. Noun Modification ('Another / Next'): When used as またの + Noun, it means 'another' or 'the next'. This is common in polite set phrases like またの機会（きかい） (another opportunity), which is frequently used in polite refusals such as またの機会にお願（ねが）いします (Let's do it another time / I'll pass for now). It is also used in the phrase またの名（な）を (alias / also known as). Additionally, the negative set phrase またとない means 'unparalleled' or 'once-in-a-lifetime' (e.g., またとないチャンス - a once-in-a-lifetime chance).

4. Social Function: また is the foundational component of common Japanese farewells, such as また明日（あした） (See you tomorrow), また後（あと）で (See you later), and またね (See ya). In phrases like また今度（こんど） (Next time again), it acts as a polite way to end a conversation or decline an invitation without being too blunt.

5. Emphatic and Related Forms: To emphasize repetition, forms like またまた (again and again) or またしても (once again) are often used. In conversation, 「またまた」 is also frequently used as a standalone phrase to express playful disbelief, skepticism, or modesty (e.g., 'Yeah, right!' or 'You're kidding!'). Additionally, the formal or literary pattern 「〜もまた」 (also / as well) is highly common (e.g., 彼（かれ）もまた被害者（ひがいしゃ）だ - 'He is also a victim').

6. Negative Forms: When used with a negative verb, また means 'will not do X again' (e.g., またしない - I won't do it again). This is different from まだ + negative, which means 'have not done X yet' or 'will not do X yet' (e.g., まだしない - I won't do it yet). To strongly express 'never again', the phrase 二度（にど）と is used with a negative verb instead of また.