You have the formal, polite, and informal forms to work with. Research has shown that learning a new language increases intelligence and combats brain-aging.
Young people mostly use these, but you can use them as well. We accommodate all levels and types of learners, from Absolute Beginner to Advanced, and KoreanClass is free for anyone to sign up. For one day, truly mean it whenever you say these words, and see how this lifts your spirit too!
However keep in mind that unless you know the person well, refusing food is seen as rude. So, for example, a boss would use informal speech with his employees because he's the superior.
Read more about how to use podcasts to learn a language. Each word in Korean is broken down into syllables which are composed of 2 to 4 characters; every syllable starts with a consonant and has a vowel in it.
Jeongmal gomawoyo! This is one of them. In fact, you can learn Hangul in just a few minutes.
But employees would use formal speech with their boss.