EVEN THOUGH 
Even though is used to express a fact, something that is real or true. ‘Even though’ precedes a statement of fact. It means ‘despite/in spite of’ the fact. It is more emphatic or stronger than ‘though’ or ‘although’.

  • Even though John is rich, he lives in a small house.
    (John is rich, but despite having money he lives in a small house.)
  • Even though she likes animals, Mary doesn’t want a dog.
    (Mary likes animals, but in spite of that she doesn’t want a dog.)
  • Even though the building was damaged, business went on as usual.
    (The building was damaged, but despite that business went on as usual.)
  • Even though I washed it several times, I couldn’t get rid of the stain.
    (I couldn’t get rid of the stain despite washing it several times.)

EVEN IF 
Even if is used in a supposition or hypothesis. It refers to an imaginary or unreal situation.

  • Even if Caroline earned a big salary, she would not buy a fast car.
    (Supposing Caroline earned a big salary. She still wouldn’t buy a fast car because she thinks they are too dangerous.)
  • Even if I had time and money, I still wouldn’t go on a cruise.
    Supposing I had time and money. I still wouldn’t go on a cruise. I have other reasons for not going.)
  • I wouldn’t wear that dress even if I got it for free!
    (Imagine getting that dress for nothing. I still wouldn’t wear it!)
  • Even if Tom was offered a job in New York, he wouldn’t accept it.
    (Supposing Tom was offered a job in New York. He wouldn’t accept it because he doesn’t like big cities.)

Although/even though and despite/in spite of are used to combine or link two contrasting statements.

Although/even though are followed by a subject and a verb.

Even though is a slightly stronger form of ‘although’.

Although and though have the same meaning and are interchangeable in most cases.

    • Although/even though it was raining, she walked to the station.
    • Although/even though he had enough money, he refused to buy a new car.
    • Although/even though Amy was wearing glasses, she couldn’t read the notice.
    • Although/even though he disapproved, he said nothing.
    • Although/even though Jack had worked hard, he failed the exam.
  • Despite/in spite of are followed by a noun, a pronoun or a verb ending in -ing.
    (The gerund, a verb ending in -ing,  is the ‘noun’ form of a verb.)

    N.B. Despite/in spite of  have the same meaning, but despite is used without ‘of’.

    • Despite/in spite of the rain he walked to the station.
    • He noticed the rain but he walked to the station in spite of it.
    • Despite being wet and tired, he walked to the station.
    • He decided to go sailing despite/in spite of the bad weather conditions.

Example:
He had enough money. He refused to buy a new car.

The above two statements can be combined as follows :

  • Although/even though he had enough money, he refused to buy a new car.
  • Despite/in spite of having enough money he refused to buy a new car.
  • He had enough money, but despite/in spite of that he refused to buy a new car.

EVEN SO 
‘Even so’ follows a statement of fact. It means ‘although that is true’ or ‘nevertheless’.

  • Our instructor was very strict. Even so, we liked him.
  • The weather was cold and wet but even so we enjoyed our trip.
  • Her English wasn’t very good but even so she managed to explain the problem.
  • His letter was full of mistakes. Even so, the effort he made was appreciated.