Since vs For with Present Perfect: The Definitive Guide

Introduction

Do you ever freeze mid-sentence, wondering whether to say “since 2019” or “for 2019”? You are not alone. The difference between since and for is one of the most common stumbling blocks for English learners at the B1–B2 level. Getting this right will instantly make your English sound more natural and precise, especially when you use the present perfect tense. In this guide, we will break down the rules, show you clear examples, and give you practice drills so you can speak with confidence.

What Is the Difference Between Since and For?

Simply put, since and for are both used with the present perfect to talk about actions or states that started in the past and continue to the present. The key difference is what they tell us about time.

• Since gives a starting point — a specific moment or event in the past. Examples: since Monday, since 2015, since I was a child.
• For gives a duration — a length of time. Examples: for three days, for a decade, for a long time.

Think of since as the “anchor” that tells you when it began, and for as the “measure” that tells you how long it has been going on.

Rules

Follow these five golden rules to master the usage:

1. Rule 1: Use “since” with a specific starting point. This can be a date (since 1990), a time (since 3 PM), a day (since Tuesday), or an event (since the meeting).
2. Rule 2: Use “for” with a period of time. This is always a quantity: for two hours, for five years, for a century.
3. Rule 3: Always use the present perfect (or present perfect continuous) with both. You cannot say “I work here since 2010.” You must say “I have worked here since 2010.”
4. Rule 4: “Since” can also introduce a clause. For example: “I have felt better since I started exercising.” Here, “since” is followed by a subject and a verb (a clause), not just a time phrase.
5. Rule 5: Do not use “since” with a duration, and do not use “for” with a starting point. “Since three years” is wrong; “for three years” is correct. “For 2010” is wrong; “since 2010” is correct.

How to Use It

Follow this simple three-step process to choose correctly every time:

1. Step 1: Identify the time expression. Look at the word or phrase that follows. Is it a date, day, event, or specific moment? Or is it a number with a time unit (like “two weeks”)?
2. Step 2: Ask yourself the question. If the answer to “When did it start?” is specific (e.g., “last summer”), use since. If the answer to “How long?” is a duration (e.g., “eight months”), use for.
3. Step 3: Check your verb. Make sure you are using the present perfect form (have/has + past participle). Example: “She has lived in Rome since 2018.” (starting point) vs. “She has lived in Rome for six years.” (duration).

Let’s look at a practical example. Imagine you started your job in March 2020. Today is March 2025. You can say, “I have worked here since March 2020″ (anchor) OR “I have worked here for five years” (duration). Both are correct, but they focus on different information.

Examples in Sentences

Here are 12 natural sentences. Notice how the grammar point is bolded for clarity.

• I have known my best friend since primary school.
• They have been married for twenty-five years.
• We have not seen that movie since last Christmas.
• He has played the guitar for a decade.
• She has worked at this hospital since 2019.
• I have felt much happier since I changed my job.
• The company has grown for several years without stopping.
• Have you studied English since you were in high school?
• My parents have lived in the same house for over thirty years.
• We have been waiting for the bus since 8:30 AM.
• Tom has been learning Spanish for only three months, but he is already fluent.
• I haven’t eaten sushi since our trip to Japan.

Common Mistakes

Even advanced learners make these errors. Let’s fix them together.

• Mistake 1: Using “for” with a starting point.
  ❌ I have lived here for 2015.
  ✅ I have lived here since 2015.
• Mistake 2: Using “since” with a duration.
  ❌ She has been a teacher since ten years.
  ✅ She has been a teacher for ten years.
• Mistake 3: Forgetting the present perfect and using the simple past.
  ❌ I work at this bank since 2020.
  ✅ I have worked at this bank since 2020.
• Mistake 4: Using “since” with a clause but forgetting the present perfect in the main clause.
  ❌ We are friends since we met in college.
  ✅ We have been friends since we met in college.
• Mistake 5: Confusing “for” and “since” in negative sentences.
  ❌ I haven’t smoked since two months.
  ✅ I haven’t smoked for two months.

Quick Summary

• Since = starting point (a specific time, date, or event).
• For = duration (a length of time).
• Both are used with the present perfect (have/has + past participle).
• Ask: “When did it start?” → use since. Ask: “How long?” → use for.
• Common errors: mixing them up, using with the wrong tense, or using a duration with “since.”

Practice Exercises

Fill in the blanks with since or for. Write your answers down, then check below.

1. I have been interested in art ______ I was a teenager.
2. They have owned that car ______ 2017.
3. We have been studying English ______ three hours.
4. She hasn’t visited her hometown ______ a long time.
5. He has worked as a chef ______ he graduated from culinary school.

Answers:

1. since (starting point: “I was a teenager”)
2. since (specific year: 2017)
3. for (duration: three hours)
4. for (duration: a long time)
5. since (starting point: “he graduated”)

Conclusion

Mastering since vs for is a small change that makes a huge difference in your fluency. Remember the simple anchor-versus-duration rule, and always pair them with the present perfect. With a little practice, you will never hesitate again.

FAQ

1. Can I use “since” with the present perfect continuous?

Absolutely. In fact, it is very common. For example: “I have been reading this book since Monday.” The continuous form highlights the ongoing nature of the action, while “since” gives the starting point. The same rules apply for choosing “since” or “for” — the tense just adds a sense of activity in progress.

2. What is the difference between “since” and “from”?

“Since” is used with the present perfect to connect the past to the present (e.g., “I have known him since 2010”). “From” is used to talk about a starting point in the past or future, but it usually pairs with “to” or “until” and is not used with the present perfect (e.g., “I worked from 9 AM to 5 PM”). You cannot say “I have known him from 2010.”

3. Is it ever correct to use “for” with a specific date?

No, not with a specific date as a starting point. “For” always requires a duration. However, you can say “for the year 2020” if you mean a length of time within that year, but this is rare and usually sounds awkward. Stick to the simple rule: “since” for a point, “for” for a period.

4. How do I answer questions like “How long have you lived here?”

You can answer with either, depending on what you want to emphasize. If you say “Since 2015,” you give the anchor. If you say “For ten years,” you give the duration. Both are correct and natural. Many native speakers choose one based on what they think the listener wants to know. If the question is “How long?” either answer works perfectly.