I have learned that there are two forms of conjugates that functions for a polite declarative sentences: 요 and ㅂ니다. However, it seems that most people only use 요 and rarely use ㅂ니다, which I also heard by a native Korean.
The native I asked answered that you as a foreign language learner would not use the form
ㅂ니다 in any situations. She also said that she rarely (or never) uses it and told me that the only situation a normal Korean uses the form is in army (male only).
I also know that news reporters at TV or flight attendants use the more polite form. However, as a foreigner, is there any chance that I shall use it in everyday life?
Sorry I should have clarified it more, but I meant that it doesn't include an idiomatic phrase like
잘 먹겠습니다 or
잘 먹었습니다, which my Korean friend used, too. I meant if a random verb would be used in ㅂ니다 form in any situation except those idiomatic phrases as a foreigner.