particle
possessive marker (archaic)
Archaic possessive use, equivalent to modern の. Now mostly seen in place names and literary contexts; often written as ヶ in such names.
The ヶ in Sekigahara derives from the old possessive particle が.
conjunction, particle
Conjunctive use meaning 'but' or 'although'. Often used to connect contrasting clauses, similar to けれども or が.
彼は若いが、しっかりしている。
He is young, but he is reliable.
努力したが、失敗した。
I tried hard, but I failed.
particle
Used to connect clauses or items in a list, often with a nuance of 'and' or 'and also'. Common in formal or written Japanese.
彼は医者であるが、作家でもある。
He is a doctor and also a writer.
particle
introductory remark marker
Used after an introductory remark or explanation to lead into the main point. Often translates as 'and', 'so', or is left untranslated.
すみませんが、駅はどこですか。
Excuse me, but where is the station?
particle
regardless of; whether ... or not
Follows the volitional or -まい form of a verb to mean 'regardless of whether...' or 'no matter...'.
行こうが行くまいが、結果は同じだ。
Whether you go or not, the result will be the same.
particle
desire/hope marker
Expresses a wish or hope, often in set phrases like ～たいものだ or ～ばいいのだが.
早く春が来るといいのだが。
I hope spring comes soon.
particle
sentence-softener; doubt marker
At the end of a sentence, softens a statement or indicates doubt, often leaving the thought incomplete. Can make a request or assertion less direct.
ちょっとお願いがあるのですが。
I have a small favor to ask (softening).
少し気になるのですが。
There is something that worries me a little.
particle
scorn marker (interjection)
Attached to a noun at the end of an interjection to express scorn or contempt. Rare and emphatic.
この馬鹿者が！
You fool! (scornful)
Search-only form; used in place names for the archaic possessive sense.
Search-only katakana form; sometimes seen in place names for the archaic possessive sense.
Topic marker; contrasts with が which marks the subject. は sets the topic, while が identifies the subject within that topic.
Modern possessive particle; が was used archaically for possession, now replaced by の except in place names and literary contexts.
Conjunction meaning 'but'; が is often more formal or written, while けれども and its variants are common in speech.
The particle が has been used since Old Japanese. Its possessive function is ancient and survives in place names. The conjunctive and sentence-final uses developed later. The exact derivation is uncertain, but it is a core native Japanese particle.