B1
即使…也 — even if
How Chinese says “even if” with 即使 and 就算, why the 也 in the second half is not optional, and how it differs from the 虽然 you already know.
即使 grants something hypothetically and says it changes nothing. 就算 is the everyday spoken version and means the same.
即使下雨，我也去。
Jíshǐ xià yǔ, wǒ yě qù.
Even if it rains, I’ll go.
就算你不同意，我也要试试。
Jiùsuàn nǐ bù tóngyì, wǒ yě yào shìshi.
Even if you don’t agree, I’m going to try.
即使下雨，我去。
即使下雨，我也去。
即使 sets up a concession and 也 is what answers it — the same both-halves shape as 虽然…但是. Without it the sentence stops halfway.
Against 虽然
This is the distinction worth holding on to, and English blurs it: even though and even if differ by one word and by everything.
虽然下雨了，我还是去了。
Suīrán xià yǔ le, wǒ háishi qù le.
Even though it rained, I went.
即使下雨，我也去。
Jíshǐ xià yǔ, wǒ yě qù.
Even if it rains, I’ll go.
虽然 concedes something that happened. 即使 concedes something that might, and often something the speaker thinks probably will not. Notice the first has 了 and the second cannot — a hypothesis has not completed.
Against 不管
即使 grants one specific case. 不管 sweeps every case aside at once. 即使下雨我也去 concedes the rain; 不管天气好不好我都去 refuses to consider the weather at all.
哪怕 in speech
哪怕 is a third version, warmer and more colloquial than either, and common in the north.
哪怕只有一点点希望，也要试。
Nǎpà zhǐyǒu yìdiǎndiǎn xīwàng, yě yào shì.
Even if there’s only the slightest hope, you have to try.