You’ve probably noticed that anglos say ‘please’ and ‘thank you’ a lot. If a request is a sandwich, these two words are the bread.
Many moons ago (early 14th century), those of a lesser station (servants and the like) would address their superiors by saying ‘if it pleases you to do this …’ The first known use of ‘please’ as a stand alone is 1667 and there haven’t been many variations since then. It’s an easy way of getting someone to do something for you.
‘Thank’ comes from ‘think’ and originally implied that the speaker would always remember the service or gift that was bestowed upon them.
Of course, once we ask someone to do us a favor, we are now in their debt. Even if the only thing they did was pass the salt, we still owe them something. Luckily a simple ‘thanks’ will suffice to save our pound of flesh.
I will admit, it can get boring saying thank you, thank you, thank you all the time, so here are some alternatives:
much obliged: similar to the Portuguese 'obrigado'
thanks a bunch: ironic
I owe you one: I will return the favor
I owe you big: I will return the favor extravagantly
cheers: very informal
you shouldn't have: used especially when someone gives you a gift
To wrap up the conversation the person being thanked then goes on to say ‘you’re welcome’ or ‘my pleasure’ which translates into ‘I got satisfaction out of passing the salt to you so actually you did me a favor, I invite you to ask me to do it again.’
Know that when anglos use these words they are expressing an ingrained morality ... forgetting your Ps & Qs is an uncivilised travesty.
Of course I can’t end this communiqué without a proper thank you, so please accept this micro e-book, ‘THE’ as a token of my appreciation for your kindness, gentle reader.