Basic Time Expressions: 오늘, 어제, 내일

In English, we use words like 'today' or 'yesterday'. Korean does the exact same thing. These words usually sit at the start of a sentence. They act like adverbs most of the time. This means they describe when the action happens. They don't need a lot of extra bits. They are quite independent words. They tell the listener the 'time frame' immediately. It is like setting the stage for a play. Once you say 어제, everyone knows we are talking past. It is very efficient and clean. Think of it like a grammar traffic light. It tells the listener when to go or stop.

1. 1Pick your time word: 오늘 (Today), 어제 (Yesterday), or 내일 (Tomorrow).
2. 2Place it at the beginning of your sentence.
3. 3Match your verb tense to the time word.
4. 4If you use 어제, use the past tense.
5. 5If you use 내일, use the future tense.
6. 6오늘 can work with present or past tense.
7. 7Do not add the particle -에 after these specific words.

Use 오늘 when talking about right now. Or use it for things happening later this evening. It is perfect for making dinner plans. Use 어제 for anything that is already finished. Did you eat a giant pizza last night? Use 어제. It helps you tell stories about your weekend. Use 내일 for your big dreams and plans. Are you going to study hard tomorrow? Use 내일. Use them in job interviews to show your schedule. Use them with friends to hang out. They are essential for booking flights and hotels too. You will find them in every conversation.

Do not use 내일 with a past tense verb. That would mean you are a time traveler. Unless you have a blue police box, don't do it. Avoid adding -에 to these three specific words. While other time words like 'Monday' use -에, these don't. It is a very common mistake for beginners. Don't use 오늘 if you mean 'right this second'. For that, you should use 지금. 오늘 covers the whole 24-hour period. Don't use 어제 for things that happened years ago. It is specifically for the day before today. Keep your time frames clear and accurate.

The biggest mistake is saying 오늘에 or 내일에. It sounds very strange to Korean ears. Just say the word by itself. Another mistake is forgetting to change the verb. If you say 어제, the verb must be past. You cannot say "Yesterday I go to school." That will confuse your Korean friends. Some people mix up 어제 and 오늘. They sound a bit similar if you speak fast. Take your time and pronounce the vowels clearly. Yes, even native speakers mess this up sometimes! Don't worry if you do it once or twice. Just correct yourself and keep talking. Practice makes perfect in time grammar.

How is 오늘 different from 지금? 지금 means 'now' or 'this instant'. 오늘 is the entire day from morning to night. Think of 지금 as a point on a line. 오늘 is a big circle around that point. What about 어제 versus 아까? 아까 means 'a little while ago' today. 어제 is a completely different day in the past. It is like looking at a calendar versus a watch. Use 내일 for tomorrow, but use 나중에 for 'later'. 내일 is specific and fixed. 나중에 is vague and could be any time. Choosing the right word makes you sound natural.