やってみよう: Man: How was the new restaurant? Woman: The food was great, ___ the chairs were very small. 女の人のせりふを選んでください。 (so / but / because) 答え: but — おいしい料理と小さないすは反対のことなので、but と言います。
so（だから）
最初の部分の結果として起きたことを言うときは so を使います。
The store was closed, so we went home.
I was tired, so I went to bed early.
やってみよう: Man: Did you watch the game last night? Woman: No. My TV was broken, ___ I listened to it on my phone. 女の人のせりふを選んでください。 (because / although / so) 答え: so — テレビがこわれていたからスマホで聞いたので、so と言います。
although は2つの文をつなぐ
2つめの部分が意外なことのとき、although で2つの文をつなぎます：Although it was late, I went out.
Although it was late, I went out.
Although I was tired, I finished my work.
やってみよう: Woman: Did you enjoy the party? Man: Yes. ___ I didn't know anyone, I had a great time. 男の人のせりふを選んでください。 (Because / Although / So) 答え: Although — 知り合いがだれもいないパーティーで楽しく過ごせたのは意外なことなので、Although で始めます。
although … but とは言わない
although か but のどちらかを使います。1つの文で両方は使いません。
Although the bus was full, we got on.
The bus was full, but we got on.
Not "Although the bus was full, but we got on." — say "Although the bus was full, we got on.". although のあとに but を加えません。
やってみよう: Man: How was the trip? Woman: Although the hotel was small, ___ 女の人のせりふを選んでください。 (but we loved it. / we loved it. / so we loved it.) 答え: we loved it. — although のあと、2つめの部分につなぎことばはいりません。
どのつなぎことば？
意味で選びましょう：理由には because、その結果起きたことには so、違いには but です。
We stayed home because it rained.
It rained, so we stayed home.
It rained, but we went out.
やってみよう: Woman: Why is the house so clean? Man: My parents are coming tomorrow, ___ I cleaned everything. 男の人のせりふを選んでください。 (but / because / so) 答え: so — 両親が来るから掃除をしたので、so と言います。