though, even though and even so
Nguyen and Alex from Vietnam and Peru writes:
  Nguyen Tu Thang from Vietnam writes: Could you please explain the use of the word though in sentences where its role seems to be nothing but an added word used at the end of sentences in conversation?
Alex from Peru writes: Is the meaning the same when we use even though and even when? I'm quite confused about this.
Roger Woodham replies:
Though can be used both as a conjunction and as an adverb
though as conjunction
We usually think of though as a conjunction as the more informal alternative of although, introducing a subordinate clause of contrast. When we use though or although, they introduce an idea that makes the statement in the main clause seem surprising:
(Al)though I was late for the meeting, I decided to go nevertheless
(Al)though the sausages were past their sell-by date, I ate them and didn't become ill.
even though
Note that we use even though as an alternative to though or although when the ideas expressed appear more extreme or surprising::
Even though the earthquake occurred ten days ago, the authorities believe it may still be possible to find survivors under the rubble.
though as adverb
In your definition of the word, Nguyen, though is used as an adverb with a meaning similar to however. Again it indicates a contrast. Used in this way, it occupies either mid or end position in a sentence and makes the previous statement or idea seem less true or appealing:
I thought Steve's essay was very good. ~ Yes, he made some good points and it was good in parts. It was a bit repetitive, though.
I drove that new convertible the other day. Very impressive. ~ Isn't it rather expensive, though?
It seems he's still suspected of the crime. His main defence, though, is that he spent the evening with his girlfriend and she seems totally credible.
even if / even when / even though
When we use even before if, when and though, it has the effect of making the ideas expressed appear more extreme or surprising. Even if is used for emphasising that although something might happen, the situation will not change:
I shall continue to work from 6 a.m. till midnight, even if it kills me.
Even if I became a millionaire, I would not stop working.
Even when is used for emphasising that although something happens on a regular basis, the situation does not change:
She checks her text messages when you least expect her to, even when she's driving.
He never stops talking and goes on and on even when other people are talking.
Even though, as we have seen, introduces a fact that makes the main statement in your sentence seem very surprising:
Even though she has a degree in business administration, all her business ventures have failed.
They made me feel as if I was one of the family, even though I'd never met any of them before.
even so
Note that even if, even when and even though are conjunctions, linking two clauses. Even so like though, meaning however, is an adverb and is used for introducing a statement that seems surprising after what has been said before.
This time he has kept all the promises he made. Even so, I don't really trust him.
I know you know this piece of music off by heart, but, even so, you should follow the score.