Both questions are correct, and both ask the same thing: which day of the week it was yesterday. The only difference is in how the sentence is built.
- What day was yesterday? is a short, direct form.
- What day was it yesterday? is the more common form in everyday speech.
If you need a quick answer, use either one. The rest of this page explains the grammar, how to answer, and a few spots where people get confused.
The short answer
| Question | Is it correct? | How it sounds |
| What day was yesterday? | Yes | Short and direct, slightly more formal |
| What day was it yesterday? | Yes | Natural and conversational |
The answer is the same either way. If today is Wednesday, you would say, “Yesterday was Tuesday.”
Why the two sentences are built differently
“What day was yesterday?”
Here, yesterday is the subject of the sentence, the thing you are asking about. It works like “What day is Christmas this year?” You are asking which weekday the word yesterday points to.
“What day was it yesterday?”
Here, it is the subject. This is the same it we use in “It is Monday” or “It is raining.” It does not stand for a real object. English just needs a subject. In this version, yesterday tells us when, like today or last night.
Compare:
- What day is it today? (not “What day is today?”)
- What day was it last week?
- What day was it yesterday?
Most English speakers use the “it” pattern for the present: “What day is it?” That is why “What day was it yesterday?” feels so natural. It is the past version of a question people already ask every day.
“What day is today?” is also correct and common, so “What day was yesterday?” follows the same pattern.
How to answer each question
Answer with the weekday that comes before today. A full sentence works well for both:
- “Yesterday was Sunday.”
- “It was Sunday yesterday.”
A short answer is fine too: “Sunday.”
Here is how it works out for each day:
| If today is… | Yesterday was… |
| Monday | Sunday |
| Tuesday | Monday |
| Wednesday | Tuesday |
| Thursday | Wednesday |
| Friday | Thursday |
| Saturday | Friday |
| Sunday | Saturday |
The only tricky one is Monday. Yesterday was Sunday, which is the last day of the week on many calendars and the first day on others. A week can start on Sunday or Monday depending on the country, but the order of the days never changes.
“Day” can mean weekday or date
The word day usually means the weekday in these questions. “What day was it yesterday?” is normally answered with “Tuesday,” not “the 14th.”
If you want the calendar date, ask a clearer question:
- What was yesterday’s date?
- What date was it yesterday?
Some people do answer “what day” with a date, so context matters. If you are unsure which one someone wants, you can give both: “It was Tuesday, the 14th.”
Where people get confused
“What day is yesterday?”
This sounds odd because is is in the present tense but yesterday is in the past. Use was: “What day was yesterday?”
Mixing up the tense inside the answer
Keep the answer in the past too. Say “Yesterday was Friday,” not “Yesterday is Friday.”
Thinking one version is wrong
Some people believe “what day was it yesterday” is sloppy, or that “what day was yesterday” is missing a word. Neither is true. Both are standard English.
Which one should you use?
- In conversation, use “What day was it yesterday?” It matches how people already ask “What day is it?”
- In writing, quizzes, or forms where you want fewer words, “What day was yesterday?” is fine.
- In English-learning exercises, both are accepted. Teachers often present them together because they show the same meaning with different structures.
Neither choice changes the answer. Pick the one that sounds more natural in your sentence.
Quick summary
“What day was yesterday?” and “What day was it yesterday?” are both correct and mean the same thing. The first uses yesterday as the subject. The second uses it as the subject and yesterday as the time. Answer with the weekday before today, and ask for the date directly if the date is what you need.
Read more about these:
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- Hear Hear vs Here Here: Which Spelling Is Correct?
- Have a Nice Weekend vs Have a Good Weekend: Is There a Difference?
- Thank You Both vs Thanks to Both of You: Which Should You Use?
I write clear, practical English lessons for everyday use. On Lingotexting, I break down grammar, vocabulary, and word types into simple ideas you can apply quickly. My focus is accuracy, real examples, and helpful visuals, so learners build confidence, improve writing, and communicate naturally in school, work, and daily life.