But: が・でも

が between two sentences means “but”: “おいしいですが、高いです” = it's good but expensive. でも does the same at the start of a sentence. Careful: this が follows a complete sentence (です, ます); it isn't the subject particle.

• この 店は おいしいですが、高いです。kono mise wa oishii desu ga, takai desuThis restaurant is good, but expensive.
• 日本語は むずかしいです。でも、おもしろいです。nihongo wa muzukashii desu. demo, omoshiroi desuJapanese is difficult. But it's interesting.
• すみませんが、ペンを かして ください。sumimasen ga, pen o kashite kudasaiExcuse me, could you lend me a pen?

が after a sentence means “but”. It links two opposing ideas in one sentence, followed by a comma. Careful: it's the same character as the subject particle が, but it follows a whole sentence, not a noun.

• 日本語は むずかしいですが、おもしろいです。nihongo wa muzukashii desu ga, omoshiroi desuJapanese is difficult, but interesting.
• 行きたいですが、じかんが ありません。ikitai desu ga, jikan ga arimasenI'd like to go, but I don't have time.

でも starts a new sentence to contrast with the previous one: “…。でも、…”. It's more conversational than が.

• この 店は たかいです。でも、おいしいです。kono mise wa takai desu. demo, oishii desuThis restaurant is expensive. But it's good.

The meaning is the same; the position and register change.

が at the end of a clause softens a request or a remark, leaving what follows hanging: すみませんが… (excuse me, but…).

• すみませんが、しゃしんを とって ください。sumimasen ga, shashin o totte kudasaiExcuse me, could you take a photo?