even:
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The word even emphasises complementary, unnecessary or unexpected actions.
ex:
- I have cleaned the entire house, i've EVEN cleaned the car.
(cleaning the car wasn't expected of me)
- He EVEN included batteries with the alarm clock he gave me as a present.
(unexpected complementary action)
- They EVEN stole the napkins.
(you wouldn't expect the thieves to also steal the worthless napkins.)
even if:
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This suggests a condition which would NORMALLY imply an action NOT to be undertaken; the condition is NOT true YET and it is unsure if it ever will be, nonetheless it will not stop the action.
- Even if it rains tomorrow, I will go run in the park.
- Even if she says she doesn't love me, I will not quit trying.
Compare with using just "even": using "if" you just suggest a condition first which would make your action to be 'complementary, unnecessary or unexpected' and then you say you will nonetheless do what you would do if the condition wasn't true.
though:
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Though is the same thing as "even if" with the important difference that the condition is already true.
(also: despite; in spite of)
- Though it is raining, I'm going out for a run in the park.
(Despite it is raining, ...)
(In spite of the fact that it is raning, ...)
Though can also be used at the end of a sentence if the condition and the action in spite of the condition aren't mentioned in the same sentence:
- It is raining outside. I'm going for a run in the park, though.
condition action
- I'm going to watch this movie. It has already begun, though.
action condition
'Although' is the same thing as 'though'.
ex.
- He's going out to the park, though it's raining.
- He's going out to the park, although it's raining.
- He's going out to the park, even though it's raining.
'Even though' means the same but it implies more explicitly that the action is unnecessary, complementary or unexpected.