Let's learn about "걱정을 했지"

걱정을 했지 : I was worried

ex)

A. 내가 출장 잘 다녀왔는지 걱정도 안 되더나? : You weren't worried if I went on a business trip well?

B. 당연히 걱정을 했지: Of course I was worried

A. 역시 우리 자기야  : As expected, my hone

[explanations]

* 내 : I (non-honourific word)

* -가 : a particle makes 내 the topic of the sentence after a word ends in a vowel

* 잘 : [=좋게] well; [=솜씨 있게] skillfully; [=주의해서] carefully, closely, attentively; [=정상적으로, 알맞게] properly; [=충분히] fully, thoroughly; [=자주] often, frequently; [=쉽게] easily

* 출장 : business trip

* -을 : a particle makes 출장 objective after a word ends in a consonant; this omitted

* 다녀오다 : go and get back, go and come back, be back

* 출장가다 = 출장을 가다 : Go on a business trip

* 출장을 다녀오다 : go and come back on a business trip

* 다녀왔다 : past tense of 다녀와다 by '-았-'

* 다녀왔는지 : 다녀왔(the stem of 다녀왔다) + -는지(whether ... or ...)

* 걱정 : [Pronunciation: 걱쩡] worry, concern, care, anxiety, apprehension, fear

* 걱정하다 = 걱정을 하다 : worry (about), be concerned[worried, anxious] (about), feel[be] uneasy (about) 

* 안 : this is equal to "not" in English

* 되다 : (1) [=새로운 신분·지위 등을 갖다] be, become (2) [=다른 것으로 변하다] turn[change] (in)to, [=발전하다] develop into (3) [=때·시기 등에 이르다] be, come, become; (나이가) reach, (formal) attain; [=경과하다] pass

* 걱정(이) 되다 : be worried

* 걱정(이) 안 되다 : be not worried

* 되더나? : 되(the stem of 되다) + -더나?(a non-honourific interrogative verb ending suffix)

* 하다 : do

* 했다 : past tense of 하다 by '-었-'

* 했지 : 했(the stem of 했다) +-지(the speaker says the speaker and the listener already knew in a friendly manner)

* -지 : (1) A sentence-final ending used when the speaker confirms and says something that the listener thought he/she already knew (2) A sentence-final ending used when the speaker talks about himself/herself or his/her thoughts in a friendly manner

* 역시 : (1) [=또한] also, too, as well; (부정문에서) either (2) [=예상했던 대로] as expected, as one expected (3) [=예전과 마찬가지로] just like before

* 우리 : (1) (주격) we, (소유격) our, (목적격) us, (소유대명사) ours, (재귀대명사) ourselves (2) (소유격) my in the sentence

* 자기 : (1) [=자신] oneself (2) (호칭) (연인을 부를 때) darling, (slng) honey; [=너, 당신] you

* 자기야 : 자기 + -야(a vocative ending suffix)