Learn Hardcore Korean: jeoneun hangsang yaksogeul jikyeoyo.

The ending -요 in 지켜요 is the standard polite style. It’s appropriate for most everyday situations—co-workers, strangers, service staff, teachers, etc. It’s friendly but respectful.

More formal: 지킵니다
Casual (to close friends/younger people): 지켜
Plain/written style: 지킨다

Why is it 저는 and not 제가?

저는 uses the topic particle -는, which frames “as for me.” It presents “me” as the topic and makes a general statement about your habit. 제가 (subject marker -가) highlights the grammatical subject more narrowly, often for new or contrasted information. Here, the topic feel (“as for me, I…”) fits well.

Do I need to say 저는 at all?

No. Korean often drops the pronoun when it’s clear from context. You can simply say:

항상 약속을 지켜요. (Natural and common) Use 저는 when you want to contrast yourself with others or explicitly emphasize “as for me.”

Why is it 약속을 and not 약속는/약속은?

약속 is the object of the verb 지키다 (“to keep”), so you use the object marker -을/를. Since 약속 ends in a consonant (ㄱ), it takes -을 → 약속을.
Using 약속은 would topicalize “promise(s)” and shift the focus: 약속은 (저는) 항상 지켜요 = “As for promises, I always keep (them).”

Can I drop the object particle 을?

In speech, yes, if the meaning stays clear:

항상 약속 지켜요. (Very natural in conversation) In careful writing or when there’s risk of ambiguity, keep -을/를.

Where should 항상 go? Are other orders okay?

Common and natural:

저는 항상 약속을 지켜요. (after the topic)
저는 약속을 항상 지켜요. (just before the verb)

Less common or only for special emphasis:

항상 저는 약속을 지켜요. (emphasizes “always I …”)
약속은 저는 항상 지켜요. (heavily topical/contrastive)

Avoid putting 항상 at the very end: …지켜요 항상 sounds unnatural as a neutral statement.

What’s the exact nuance of 지키다 here? Any useful collocations?

지키다 means “to keep/observe/protect.” With 약속, it’s the set phrase “to keep a promise.” Other common collocations:

비밀을 지키다 (keep a secret)
법/규칙을 지키다 (obey the law/rules)
시간을 지키다 (be punctual; keep time)
자리를 지키다 (stay at one’s post) Antonym: 약속을 어기다 (break a promise)

Why is it 지켜요 and not 지키어요?

It’s a regular contraction. Stem 지키- + -어요 → 지키어요 → contract 키 + 어 to 켜 → 지켜요.
Similarly, 피우어요 → 피워요, 가르치어요 → 가르쳐요.

How do I pronounce the sentence naturally?

저는: [저는] (jeo-neun)
항상: [항상] (hang-sang)
약속을: due to tensification and liaison, [약쏘글] (yak-ssogeul). Revised Romanization writes it “yaksogeul,” but you’ll hear the double-s sound.
지켜요: [지켜요] (ji-kyeo-yo)

Putting it together (sound-based): jeo-neun hang-sang yak-ssogeul ji-kyeo-yo.

How do I make this more formal or more casual?

Very formal/presentational: 저는 항상 약속을 지킵니다.
Standard polite (original): 저는 항상 약속을 지켜요.
Casual: 난 항상 약속 지켜.
Texty/colloquial contraction: 전 항상 약속 지켜요. (전 = 저는)

How do I ask it as a question?

Just use rising intonation:

항상 약속을 지켜요? (Do you always keep your promises?) More polite toward the subject (you/honorific):
항상 약속을 지키세요?

Does 지켜요 here mean a habit? Could I say 지키고 있어요?

Yes, plain present 지켜요 commonly expresses a habitual/general truth in Korean.
지키고 있어요 is progressive (“am keeping [it] right now”), which is rare/narrow for promises unless you mean you’re currently honoring a specific commitment in progress.

Any pitfalls with negation like “not always” vs “never”?

“Not always”:
- 항상 지키지는 않아요. (natural contrastive negation)
- or 항상 약속을 지키지 않아요 (can sound like you usually don’t)
“Never”:
- 절대 약속을 안 지켜요. / 약속을 전혀 지키지 않아요. Be careful: 항상 안 지켜요 is often used to mean “I never keep [them],” but it can be ambiguous. Use 절대/전혀 for clarity.

What’s the difference between 항상, 늘, 언제나, and 맨날?

All can mean “always,” but:

항상: neutral, very common.
늘: slightly literary/soft; also common in speech.
언제나: a bit formal/emphatic.
맨날: very colloquial; can nuance “all the time/every day.” All fit here except 맨날, which sounds more casual: 전 맨날 약속 지켜요 is colloquial.

Why is it 을 and not 를 after 약속?

Use -을 after a final consonant and -를 after a final vowel:

약속(ㄱ) → 약속을
시간(ㄴ) → 시간을
차(ends with vowel) → 차를