Even if, although, and yet: ても vs のに vs くせに by how much complaint they carry, and the connectors that echo them.
〜ても V-te + も / i-adj: -くても / N・na-adj + でも
Verb/i-adj (te-form) + も; noun/na-adj + でも. Means 'even if' or 'even though' — the result does not change.
雨が降っても試合はあります。 Even if it rains, the game will be held.
〜のに V/i-adj plain + のに / N・na-adj + なのに
Plain form + のに (na-adj/noun + なのに). Means 'although / in spite of', with surprise, disappointment or complaint about an unexpected result.
たくさん勉強したのに、試験に落ちた。 Even though I studied a lot, I failed the exam.
〜くせに V/i-adj plain + くせに / N + のくせに / na-adj + なくせに
Plain form + くせに (noun + のくせに, na-adj + なくせに). Means 'even though', with strong criticism or contempt for the subject.
知っているくせに教えてくれない。 Even though he knows, he won't tell me.
ところが S1。ところが、S2
Sentence + ところが + sentence. Means "however / but", introducing a result that is contrary to what was expected.
晴れると思った。ところが、雨が降った。 I thought it would be sunny. But it rained.
それにしても S1。それにしても、S2
それにしても + sentence. Means "even so / still", admitting a point but stressing that something goes beyond expectation.
夏だ。それにしても今日は暑すぎる。 It's summer. Even so, today is too hot.
確かに 確かに + S (〜が / 〜けど)
確かに + sentence. Means "certainly / indeed", agreeing that something is true, often before adding "but …".
確かに、この店は少し高い。 Indeed, this shop is a bit expensive.