Present and Past Using the Same Principle

The rule you learned for the present tense ( -아요/-어요 ) is exactly the same rule you use for the past tense ( -았어요/-었어요 ).

You do not need to learn a whole new conjugation system. If you know how to choose 아 or 어 for the present, you just add the past tense marker ( ㅆ ) to that same choice.

Core takeaway: Present and past use the same a/eo choice

For stems ending in a consonant, you simply add -아요 or -어요 for the present, and -았어요 or -었어요 for the past.

Vowel ㅏ or ㅗ

잡다 → 잡아요 → 잡았어요

Other Vowels

먹다 → 먹어요 → 먹었어요

The exact same vowel contractions and drops you learned in the previous lessons happen in the past tense too. Because the past tense starts with the same 아/어 sound, the vowels merge in the exact same way.

Contractions

Dictionary · Present · Past

보다 · 봐요 · 봤어요

마시다 · 마셔요 · 마셨어요

Dropping the ㅡ Vowel

Dictionary · Present · Past

쓰다 · 써요 · 썼어요

Just as 하다 changes to 해요 in the present tense, it changes to 했어요 in the past tense. This applies to all verbs and adjectives that end in -하다 .

Dictionary · Present · Past

하다 · 해요 · 했어요

운동하다 · 운동해요 · 운동했어요

Note: A common mistake is trying to add -았어요 to the original stem (하았어요). Remember that 하다 transforms to 해- before adding the final ending!