Even if does not mean the same as even though.
Even though is used in cases where though and although are also possible. Even though just happens to be more emphatic.
- I bought that laptop though / although / even though it was expensive.
- Even though / although she worked hard, she didn’t pass the test.
- Even though she was the most deserving candidate, she didn’t get the job.
- Even though she is rich and famous, she is not exactly a favourite with her neighbours.
Even if means ‘whether or not’. It is used to talk about the probable and improbable results of imaginary situations.
- I will not leave my company even if I get a better job abroad. (Here I am talking about an imaginary situation. I haven’t received any job offers from abroad. I am merely saying what I would do if I received a better job offer from abroad.)
- I did not leave my company even though I got a better job abroad.
Another example is given below.
- I will not sell my car even if she offers me 5000 dollars. (Imaginary situation and its probable result)
- I did not sell my car even though she offered me 5000 dollars. (Real situation)
- Even if I had a few hundred dollars to spare I wouldn’t go shopping. (This is a bit like saying: Just imagine I had a few hundred dollars to spare, I still wouldn’t go shopping.)
- Even though I had a few hundred dollars to spare, I didn’t go shopping. (Here we are talking about a real situation in the past.)
Even so means ‘however’. It is a transitional adverb. It doesn’t connect two clauses. It merely shows how the ideas expressed by the two clauses are related. It is used to introduce a fact that might seem surprising in the context of what has been said before.
- She is not very attractive. Even so, you can’t help liking her.
- Janet was the prettiest girl in my class. Even so, she was not popular with the boys.