Introduction
Do you ever freeze mid-sentence, wondering whether to say “for five years” or “since five years”? You are not alone. The difference between for and since is one of the most common challenges for ESL learners, even at the B1–B2 level. Getting this right will make your English sound instantly more natural and precise, especially when using the present perfect tense.
What Is the Difference Between For and Since?
Both for and since are used with the present perfect to talk about actions or states that started in the past and continue to the present. However, they answer different questions:
- For answers “How long?” – it expresses a duration of time (a period).
- Since answers “From when?” – it expresses a starting point (a specific moment).
Think of for as a measurement of time (like a ruler) and since as a marker on a timeline (like a pin). This simple mental image will help you choose correctly every time.
Rules
Follow these five essential rules to master for and since:
- Use “for” + a period of time. This includes durations like two hours, three days, ten years, a long time. Example: “I have lived here for a decade.”
- Use “since” + a specific point in time. This includes dates, times, or past events like Monday, 2019, 8 o’clock, I was a child. Example: “I have lived here since 2014.”
- Both are used with the present perfect for unfinished actions. If the action is finished, use the past simple: “I lived there for five years (but I moved away).”
- Never use “since” with a duration of time. ❌ “I have worked here since three years.” This is always wrong.
- Never use “for” with a specific starting point. ❌ “I have worked here for 2020.” This is also always wrong.
How to Use It
Using for and since correctly is a simple three-step process. Let’s break it down:
Step 1: Identify the time expression
Look at the time word in your sentence. Is it a duration (like “six months”) or a starting point (like “January”)?
Step 2: Choose your word
If it is a duration, choose for. If it is a starting point, choose since.
Step 3: Build your sentence
Place the time expression after for or since, and use the present perfect (have/has + past participle) for the main verb.
Let’s practice: “She has been a teacher for twelve years” (duration). “She has been a teacher since 2012″ (starting point). Both sentences are correct, but they focus on different information.
Pro tip: If you are unsure, try asking yourself: “Can I replace this with ‘a period of time’?” If yes, use for. If you can replace it with “a specific date or event,” use since.
Examples in Sentences
Here are 15 clear examples showing for and since in action. Notice how the bolded grammar point works with the present perfect:
- I have known my best friend for twenty years.
- We have lived in this apartment since 2018.
- He has studied English for three hours today.
- She has worked at the hospital since last March.
- They have been married for a decade.
- I have not seen that movie since 2015.
- My brother has played the guitar for five years.
- We have had this car since 2020.
- She has felt sick for two days.
- He has lived in London since he graduated.
- I have been a vegetarian for six months.
- They have owned that restaurant since 2009.
- She has practiced yoga for an hour every morning.
- We have been friends since primary school.
- The company has grown for ten consecutive years.
Common Mistakes
Even advanced learners slip up on these. Here are five frequent errors and how to fix them:
- ❌ I have been here since two hours. ✅ I have been here for two hours. (Remember: “two hours” is a duration, so use for.)
- ❌ She has worked here for 2019. ✅ She has worked here since 2019. (A year is a specific point, so use since.)
- ❌ We have known each other since a long time. ✅ We have known each other for a long time. (“A long time” is a period, not a point.)
- ❌ He has been sick since Monday morning. ✅ He has been sick since Monday morning. Wait – this one is actually correct! A common mistake is overthinking. Trust your rule: “Monday morning” is a specific point, so since is right.
- ❌ They have lived in Spain since five years. ✅ They have lived in Spain for five years. (Duration = for.)
Notice a pattern? The most common mistake is using since with a duration. Always double-check that you are not doing this.
Quick Summary
- For + duration (e.g., for 3 days, for ages, for a week).
- Since + starting point (e.g., since 1999, since Tuesday, since I was born).
- Both are used with present perfect for ongoing actions.
- Ask yourself: “How long?” → for. “From when?” → since.
- Avoid mixing them up: never “since + duration” or “for + point.”
Practice Exercises
Test yourself with these five fill-in-the-blank questions. Choose for or since:
- I have been a doctor ______ 2011.
- She has lived in Paris ______ five years.
- We have not seen him ______ last Friday.
- He has played soccer ______ he was a child.
- They have owned this house ______ three decades.
Answers:
- since (2011 is a specific year)
- for (five years is a duration)
- since (last Friday is a specific day)
- since (he was a child is a specific point/event)
- for (three decades is a period)
Conclusion
Mastering for vs since is a small change that makes a huge difference in your English fluency. Remember the golden rule: for measures the length, since marks the start. Practice daily, and soon it will feel automatic.
FAQ
1. Can I use “for” and “since” with other tenses?
Yes! While they are most common with the present perfect, you can also use them with the past perfect (“I had lived there for 10 years before I moved”) and the present perfect continuous (“She has been studying since 9 AM”). However, avoid using them with the simple past for unfinished actions: “I lived there for 10 years” implies it is finished.
2. What is the difference between “since” and “from”?
“Since” is used with the present perfect to show an action continuing to now. “From” is usually paired with “to” to show a full period: “I work from 9 to 5.” You cannot say “I have worked here from 2020” – you must say “since 2020” because the action is still ongoing.
3. Is “since” always followed by a past tense clause?
Not always. “Since” can be followed by a specific time (“since 2020”), a date (“since Monday”), or a clause with a past simple verb (“since I was a child”). The main clause uses the present perfect, but the clause after “since” often uses the past simple to indicate when the action started.
4. Can “for” be omitted in informal English?
In very informal spoken English, “for” is sometimes dropped before “ages” or “a long time” (e.g., “I haven’t seen you ages”). However, this is not standard grammar and should be avoided in writing or formal speech. Always include “for” to be safe and correct.