These two expressions are often confused but they are not interchangeable. Even though means ‘despite the fact that’. It shows contract. It is more emphatic than although and though.
- Even though I didn’t know anybody at the party, I had a nice time. (= Despite the fact that I didn’t know anybody at the party, I had a nice time.)
- I bought that necklace even though it was expensive. (= I bought that necklace in spite of the fact that it was expensive.)
- Even though she was angry with him, she said nothing. (= Although / though she was angry with him, she said nothing.)
Even if means ‘whether or not’. It is mainly used to talk about unreal or imaginary situations.
- Even if I become a millionaire, I will always lead a simple life.
Here the speaker is not a millionaire at the moment. He is merely saying what would happen if he were a millionaire. Here we are talking about an unreal situation and its probable result.
- Even though he is a millionaire, he leads a simple life. (= Although he is a millionaire, he leads a simple life.)
Here we are talking about a real situation. The person is a millionaire.
- I will not be able to finish that assignment even if they extend the deadline by a few weeks.
Here the reference is to an imaginary situation.
- I could not finish that assignment even though they extended the deadline by a few weeks. (= Although they extended the deadline by a few weeks, I could not finish that assignment.)
More examples are given below.
- Even though she passed the test, she didn’t get admission to the college of her choice.
- Even if she passes the test, I don’t think she will get admission to the college of her choice. (I am merely guessing.)