This expression is used to describe something which occurs repeatedly or a person who performs some action repeatedly or regularly.

It is often used together with 곧잘, 자주, 가끔.

The form '-고는 하다' is a variant of this form.

Details

1. Only verbs can come before -곤 하다.

그 여자는 가끔 예쁘곤 했다. ✕

2. Because '-곤 하다' is used to describe something customarily done, similar to a habit, it sounds strange when used to describe something that always happens, without exception.

학교 수업은 매일 9시에 시작하곤 해요. ✕

Class always starts at 9:00, without exception, so -곤 하다 therefore cannot be used.

3. The expression -곤 하다 also cannot be used to describe situations that do not repeat or that continue to a certain degree.

제니는 3년 전에 고등학교를 졸업하곤 했어요. ✕

High school graduation normally occurs only once in a person's life, so -곤 하다 cannot be used.

고등학교 때 그 가수를 좋아하곤 했어요. ✕

Here, -곤 하다 cannot be used because it is impossible to repeatedly like and then not like a singer as if it were a habitual occurrence during a particular time period.

5년 동안 이 회사에서 일하곤 했어요. ✕

Here, -곤 하다 cannot be used because it would mean the speaker worked for five years, quit the company, and then repeated the entire process multiple times.

Kimchi Reader

Indicate a habitual action of the present or past.

Details

Usage

Often used together with words like 곧잘, 자주, 가끔