One is formal (used towards older people, senior colleagues, strangers), the other would be used for friends or close family. Thank you and thanks are formal/informal.
One of the formal ways to say "thank you" because I've seen more than one way.
It's easy, for example 안녕하세요 the first letter is 아 and then you put the letters on the bottom: 안, then you continue and there's the word. A little practice is what you need.☺
as far as i know, it is the bare infinitive form of the verb. when u use the verb, u have to "put" it in the correct tense (in this case is present simple, so it becomes 고맙슴니다). Study well
I think it's just the way the computer generated voice sounds but i swear i hear an L in the word but there isn't a ㄹ
Both worked for me(I like to get to level 3 so I answer with different answers sometimes)