See Start, Progress, and Completion on a Single Timeline

Instead of memorizing separate grammar rules for every situation, we can look at an action as a simple timeline.

An action typically goes through three main stages:

Start: The moment the action begins.

Progress: The period when the action is actively happening.

Completion: The point when the action is finished.

Let's see how Korean expresses these stages naturally.

Using -기 시작하다

To express the start of an action, attach -기 시작하다 to the verb stem.

This pattern combines a verb turned into a noun form (-기) with the verb "to start" (시작하다). Since you are usually talking about an action that has already begun, it is most commonly used in the past tense.

Verb · Start Form

읽다

to read · 읽기 시작했어요

I started reading.

하다

to do · 하기 시작했어요

I started doing it.

Using -고 있다

Once an action has started and is currently happening, we use -고 있다 .

This expresses that the action is in progress right now.

Verb · Progress Form

읽다

to read · 읽고 있어요

I am reading.

하다

to do · 하고 있어요

I am doing it.

Completion with Adverbs

Many learners look for a special grammar ending to show that an action is fully complete. In Korean, you do not always need a complex ending. The basic past tense combined with time adverbs does the job perfectly.