though 常表示一些已经确定的消息
而if由它本身所带的“如果”的含义，表示了一种对假设信息的不确定。
even if 与 even though 这两个词组大致意思相当，但强调的侧重有所不同。
《麦克米伦字典》上的解释：
even if: used for emphasizing that although something may happen or may be true,
another situation remains the same
e.g.He's determined to prove his innocence, even if he has to go to the highest court in the land.
even though: used for introducing a fact that makes the main statement in your sentence very
surprising
e.g. Most of us ignore this good advice, even though we know it to be true.
e.g. Even though I have a master's degree in business administration, I can't fill out my tax form.
even though 和 even if 均可用于引导让步状语从句，其有细微区别：
1. even if 一般引导的是把握不大或假设的事情，相当于汉语的“即使”“纵然”“就算”“哪怕”。如：
Even if we achieve great success in our work, we should not be proud. 即使我们在工作中取得了巨大成绩，也不应该自满。
They’ll stand by you even if you don’t succeed. 即使你不成功，他们也会支持你。
Even if I have to walk all the way I’ll get there. 即使我得一路走着去，我也要走到那里。
Even if it rains tomorrow, we won’t change our plan. 即使明天下雨，我们也决不改变计划。
For my part, I plan to go to the party even if you decide not to go. 至于我，即使你决定不去参加晚会我也会去的。
Even if you saw him pick up the money, you can’t be sure he stole it. 就算你看见是他拾起的钱，你也不能肯定钱就是他偷的。
正因为even if从句的内容通常是假设性的，所以有时还可用于虚拟语气；这样用的even if 与单独使用的if比较接近。如：
Even if he had the money, he wouldn’t buy it. 他即使有钱也不会买它。
I would have married her even if she had been penniless. 即使她身无分文，我也会和她结婚。
Even if he knows it, he'll not let out the secret.（不确定他是否知道这个秘密）.
2. even though 引导的从句引出的是事实，内容往往是真实的，主要用于引出不利用于主句情况的信息，相当于汉语的“尽管”“虽然”。如：
He went out even though it was raining. 尽管在下雨，他还是出去了。
Even though it’s hard work, I enjoy it. 虽然工作艰苦，我还是很喜欢。
He’s the best teacher even though he has the least experience. 他尽管经验最少，但教得最好。
Even though I didn’t know anybody at the party, I had a nice time. 尽管这次聚会上我谁也不认识，我也玩得挺痛快。
这样用的even though与though或although的意思比较接近，许多时候可以互换（注意：英语可以说though和even though，但不能说even although）。如：
Even though [Thought, Although] I felt sorry for him, l was secretly pleased tha t he was having difficulties. 虽然我为他感到惋惜，但对他的困难却暗自高兴。
Even though [Thought, Although] we all tried our best, we lost the game. 虽然我们已尽了最大的力量，但还是输了。
Even though he was late, he was not criticized by the teacher．虽然他晚了, 可他并没有受到老师的批评。
3. 不过，在实际语言运用中，even if与even though有时也可不加区别地混用。如：
Even if [Even though] she laughs at him, he likes her. 尽管她嘲笑他，他还是很喜欢她。
We thoroughly understand each other, even if [even though] we don’t always agree. 我们彼此非常了解，虽然有时候也有一些分歧。