Answer:
I use formal deference whenever I need to speak to someone who is in a higher social or professional position than mine, such as teachers, medical lawyers, my boss, among others. I also use this kind of deference with people older than me, whom I am not intimidating, always calling them Mr. and Mrs.
Informal deference, on the other hand, I use with people in my family who are older than me, like my parents and grandfather, for example. In this case, I avoid using girias and use an informal but respectful language with them.
Explanation:
Deference is a term that refers to a language of respect and consideration for older people, or in some way, people who occupy a social or professional position greater than yours.
The deference can be formal or informal depending on the degree of intimacy between related people. In formal deference, formal terms and cultured language are used. In informal deference, a less elaborate language is used, but always with respect.