Let's learn about "춥나?"

춥나? : Are you cold?

[other expressions]

- 춥니? (to the younger people or friends)

- 춥나? (to the younger people or friends)

- 춥냐? (to the younger people or friends)

- 추워? (to the younger people or friends)

- 추우니? (to the younger people or friends)

- 추운가? (to the younger people or friends)

- 춥지? (to the younger people or friends)

- 춥나요? (honourific by '-요')

- 추워요? (honourific by '-요')

- 추운가요? (honourific by '-요')

- 춥지요? (honourific by '-요')

- 춥죠? (honourific by '-요'; -죠? is a short form of -지요?)

- 춥습니까? (formal; more honourific by '스')

[explanations]

* 추운 : cold

* 춥다 : [ㅂ 불규칙] be cold

* 춥게 : an adverb form of 추운 by '-게'

* 쌀쌀한 : (1) chilly (2) indifferent, unconcerned, disinterested, distant, unfriendly

* 쌀쌀하다 : a verb form of 쌀쌀한

* 쌀쌀하게 : an adverb form of 쌀쌀한 by '-게'

* 추워?  : 춥(the stem of 춥다; ㅂ changed into 우) + -어(a non-honourific interrogative verb ending suffix)

* 추우니? : 춥(the stem of 춥다; ㅂ changed into 우) + -니(a non-honourific interrogative verb ending suffix)

* 추운가? : 춥(the stem of 춥다; ㅂ changed into 우) + -ㄴ가?(a non-honourific interrogative verb ending suffix)

* ㅂ 불규칙 : the second ㅂ of 춥다 is not 'B' sound but 'V' sound and V consists of ㅂ + 옛이응  ‘ㆁ’. these days  V sound changed into '우' for easy pronunciation

* See : https://m.blog.naver.com/nurisejong/221050681781

* 춥습니까? : 춥(the stem of 춥다) + -스(a suffix makes a verb more honourific) + -ㅂ니까?(an honourific interrogative verb ending suffix)

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

* a verb + -나? / -어? / -ㄴ가? / -지? + -요 : an honourific ending suffix

* a verb + -습니까? : an honourific interrogative verb ending suffix by '스-'