Let's learn about "저 모르세요?"

저 모르세요? : Don't you know me?

[other expressions]

- 나 모르니? (to younger people or friends)

- 나 모르나? (to younger people or friends)

- 나 모르냐? (to younger people or friends)

- 나 몰라? (to younger people or friends)

- 저 모르나요? (honourific by '-요')

- 저 몰라요? (honourific by '-요')

- 저 모르세요? (more honourific by '-시')

- 저 모르셔요? (more honourific by '-시')

- 저 모르십니까? (formal; more honourific by '-시')

[explanation]

* 나 : I (non-honourific word)

* 저 : I (honourific word)

* -를 : a particle makes 나 / 저 objective after a word ends in a vowel; this omitted

* 모르다 : not know

* 몰라? : 모르(the stem of 모르다; 모르 + -아 contracted into 몰라) + -아?(a non-honourific interrogative verb ending suffix)

* 모르세요? : 모르(the stem of 모르가) + -시(s suffix makes a verb more honourific) + -어?(an interrogative verb ending suffix) + -요(an honourific verb ending suffix)

* 모르셔요? : 모르(the stem of 모르가) + -시(s suffix makes a verb more honourific) + -여?(an interrogative verb ending suffix) + -요(an honourific verb ending suffix)

* 모르십니까? : 모르(the stem of 모르다)  + -시(s suffix makes a verb more honourific) + -ㅂ니까?(an  honourific interrogative verb ending suffix)

* a verb + -니? / -나? / -냐? / -아? : a non-honourific interrogative verb ending suffix

* a verb + -나? / -아? + -요 : an honourific verb ending suffix

* a verb + -세요? / -셔요? / -십니까? : an  honourific interrogative verb ending suffix  by '-시' / '-요'