Since vs For: Have you ever wondered whether to say “I have lived here since 2020” or “I have lived here for six years”? Both sentences are grammatically correct, but they describe time in different ways.
The difference between since vs for is easy to understand once you know what each word tells us about time.
Since identifies when an action or situation began. For describes how long an action or situation lasts.
For example, “She has worked here since January” tells us when her employment started. “She has worked here for several months” tells us the length of her employment.
Both words are especially common with the present perfect and present perfect continuous tenses. However, they also appear in other grammar structures.
In this guide, you’ll learn the meanings, grammar rules, common mistakes, sentence patterns, and practical examples that will help you use since and for correctly in everyday American English.
QUICK ANSWER
Use since + starting point, such as Monday, 2020, or last summer. Use for + duration, such as three days, two years, or a long time.
| Since | For |
|---|---|
| Since Monday | For three days |
| Since 2020 | For several years |
| Since January | For six months |
| Since I graduated | For a long time |
| Starting point | Length of time |
TL;DR — Since vs For
- Since tells us when something started.
- For tells us how long something lasts or lasted.
- Use since + starting point.
- Use for + duration.
- Both commonly appear with the present perfect and present perfect continuous.
- Since can introduce a time clause, such as since I moved here.
- For can describe completed or ongoing periods.
- Since can also mean because.
- The correct tense depends on whether the situation is continuing or completed.
1. What Does Since Mean?
Since commonly identifies the starting point of an action or situation that continues until a later reference time, often the present.
It answers the question: Since when?
Examples
- I have lived here since 2020.
- She has worked at the company since January.
- We have been friends since childhood.
- He has felt better since Monday.
In each example, since tells us when the situation began.
Grammar Pattern
Since + starting point
Common starting points include:
- Since yesterday
- Since last week
- Since 2019
- Since 8 AM
- Since I graduated
Important: Since can introduce a noun phrase or a time clause.
Example: I have known her since we were children.
2. What Does For Mean?
For is a preposition that commonly describes the duration of an action or situation.
It answers the question: How long?
Examples
- I have lived here for several years.
- She studied for three hours.
- We waited for twenty minutes.
- They have been married for a decade.
These sentences tell us how long an activity or situation lasted or has lasted.
Grammar Pattern
For + duration
Examples:
- For two hours
- For three days
- For six months
- For several years
- For a long time
Unlike since, for does not identify the starting date by itself.
3. Since vs For: Key Differences
The main difference between since and for is the type of time information they provide.
Since identifies a starting point.
For measures a duration.
| Feature | Since | For |
|---|---|---|
| Main time meaning | Starting point | Duration |
| Answers | Since when? | How long? |
| Followed by | A time point or time clause | A period of time |
| Common with present perfect | Yes | Yes |
| Can appear with other tenses | Yes | Yes |
| Example | Since 2021 | For several years |
| Other meanings | Because | Purpose, benefit, reason |
Compare
Since: I have worked here since 2021.
For: I have worked here for several years.
Both can describe employment continuing into the present, but they provide different information.
The first gives the starting year. The second gives the length of employment.
4. When Should You Use Since?
Use since when you want to identify the time at which something began.
Dates
- She has lived here since January 2022.
- I have worked remotely since March.
Days
- We haven’t spoken since Monday.
- He has been sick since Friday.
Clock Times
- I’ve been awake since 6 AM.
- They have been waiting since noon.
Events
- She has felt happier since her graduation.
- I haven’t seen him since the wedding.
Clauses
- I have known her since we were children.
- He has improved since he started practicing.
Writing tip: Use since when you can identify a starting point, even if that starting point is an event rather than a date.
5. When Should You Use For?
Use for when you want to describe the length of an action or situation.
Minutes and Hours
- I waited for ten minutes.
- She studied for four hours.
Days and Weeks
- We stayed there for five days.
- He has been absent for two weeks.
Months and Years
- They have lived here for eight months.
- She has worked in education for ten years.
Indefinite Durations
- I haven’t seen you for a long time.
- They talked for a while.
Completed vs Ongoing Actions
Completed: I worked there for three years.
Ongoing: I have worked there for three years.
The time expression remains the same, but the tense changes the meaning.
6. Since vs For with the Present Perfect
The present perfect tense connects past events or situations with the present.
Both since and for commonly appear with this tense.
Present Perfect Structure
Subject + have/has + past participle
Examples with Since
- I have lived here since 2020.
- She has known him since childhood.
- They have owned the house since 2018.
Examples with For
- I have lived here for several years.
- She has known him for a long time.
- They have owned the house for many years.
Comparison
| Since | For |
|---|---|
| I have worked here since Monday. | I have worked here for several days. |
| She has studied English since 2021. | She has studied English for several years. |
| We have been friends since childhood. | We have been friends for many years. |
The present perfect commonly describes situations that began in the past and continue into the present.
Important Note About Stative Verbs
Some verbs describe states rather than actions.
Examples include know, own, and believe.
Natural: I have known her for ten years.
Unnatural in ordinary usage: I have been knowing her for ten years.
7. Since vs For with the Present Perfect Continuous
The present perfect continuous tense emphasizes an activity that began in the past and has continued or been repeated up to the present. It can also describe a recently ended activity with a present result.
Structure
Subject + have/has + been + verb-ing
Since Examples
- I have been studying since 8 AM.
- She has been working since Monday.
- They have been waiting since noon.
For Examples
- I have been studying for three hours.
- She has been working for five days.
- They have been waiting for thirty minutes.
Difference in Meaning
Since: He has been exercising since January.
For: He has been exercising for several months.
The first identifies the starting point. The second measures the duration.
Present Perfect vs Present Perfect Continuous
I have worked here for five years.
This emphasizes the employment situation.
I have been working here for five years.
This can emphasize the ongoing activity of working.
Both are natural in this context.
8. Since vs For in Past and Future Tenses
Both words can appear in sentences about past and future events, but their uses differ.
For with the Simple Past
For commonly describes completed periods.
- I lived in Chicago for three years.
- She studied for two hours.
- They stayed for a week.
Since with the Past Perfect
Since can identify a starting point relative to a past reference time.
- By 2020, she had worked there since 2015.
- When I visited, they had been living there since January.
For with Future Tenses
- I will stay for two weeks.
- She will travel for ten days.
- They will work on the project for six months.
Since and For with the Future Perfect
Since: By January 2027, I will have been working here since January 2022.
For: By January 2027, I will have been working here for five years.
Both are grammatical.
However, the duration version is often more natural when describing a future milestone.
9. Since with Clauses, -ing Forms, and Negative Sentences
Since can introduce more than just dates or time expressions.
It can also introduce clauses and shortened constructions.
Since + Past Simple Clause
Example: I haven’t seen him since he moved away.
The clause he moved away identifies the completed event that marks the starting point.
Since + -ing Form
Example: Since moving here, I have made many friends.
This shortened construction is natural when the intended subject is clear.
Since in Negative Sentences
Example: I haven’t spoken to her since Monday.
This means Monday is the reference point from which the period without speaking is measured.
For in Negative Sentences
Example: I haven’t spoken to her for three days.
This describes the length of time without speaking.
Comparison
| Since | For |
|---|---|
| I haven’t seen her since Monday. | I haven’t seen her for three days. |
| He hasn’t called since last week. | He hasn’t called for several days. |
| We haven’t met since graduation. | We haven’t met for years. |
Both are correct, but they answer different time questions.
10. Since vs For vs Ago
Ago is another common time expression that learners sometimes confuse with since and for.
Ago measures backward from the present to a past point.
Examples
Since: I have lived here since 2021.
For: I have lived here for several years.
Ago: I moved here several years ago.
Comparison Table
| Word | Function | Example |
|---|---|---|
| Since | Starting point | Since 2021 |
| For | Duration | For five years |
| Ago | Time before now | Five years ago |
Common Mistake
Incorrect: I have moved here five years ago.
Correct: I moved here five years ago.
Use the simple past for a completed event located at a definite time in the past.
11. Since vs For vs During and From
During and from are other time expressions that learners sometimes confuse with since and for.
Since
Identifies a starting point.
Example: I have worked here since 2021.
For
Describes duration.
Example: I have worked here for several years.
During
Identifies an event or period in which something happens.
Example: I took notes during the meeting.
From
Can introduce the beginning of a period, especially when paired with to or until.
Example: I worked there from 2021 to 2024.
Comparison
| Word | Main Function | Example |
|---|---|---|
| Since | Starting point | Since Monday |
| For | Duration | For three days |
| During | Within an event or period | During class |
| From | Beginning of a range | From Monday to Friday |
Writing tip: Use from … to … when both the beginning and ending points are specified.
12. How Long vs Since When: Asking Questions
One useful way to choose since or for is to think about the question being answered.
How Long?
Use how long when asking about duration.
Question: How long have you lived here?
Answer: I have lived here for five years.
Since When?
Use since when when asking about a starting point.
Question: Since when have you lived here?
Answer: I have lived here since 2021.
When?
Use when when asking about the time of an event.
Question: When did you move here?
Answer: I moved here in 2021.
Comparison
| Question | Example Answer |
|---|---|
| How long have you worked here? | For three years. |
| Since when have you worked here? | Since 2023. |
| When did you start working here? | In 2023. |
Note: Since when? can also express surprise or disbelief in conversation.
Example: Since when do you like spicy food?
In this sentence, the speaker may be surprised rather than simply asking for a date.
13. Ever Since, Since Then, and Other Expressions
Both words appear in several common English expressions.
Ever Since
Emphasizes that something has continued from a particular time.
Example: Ever since she moved, we have stayed in touch.
Since Then
Means from a previously mentioned time until a later reference time, often now.
Example: He graduated in 2020 and has worked as a designer since then.
It’s Been … Since
Used to describe the time that has passed after an event.
Example: It’s been three years since I graduated.
For a While
Means for a period of time.
Example: Let’s sit here for a while.
For Ages
Means for a very long time.
Example: I haven’t seen her for ages.
Since Meaning Because
Since can introduce a reason.
Example: Since it was raining, we stayed home.
Here, since means because, not starting from a particular time.
14. Common Since vs For Mistakes
Many English learners confuse starting points with durations.
| Incorrect | Correct | Explanation |
|---|---|---|
| I have lived here since five years. | I have lived here for five years. | Five years is a duration. |
| She has worked here for 2020. | She has worked here since 2020. | 2020 is a starting point. |
| We have waited since two hours. | We have waited for two hours. | Two hours is a duration. |
| I have known him for Monday. | I have known him since Monday. | Monday is a starting point. |
| I have moved here five years ago. | I moved here five years ago. | Ago normally accompanies a past-time construction. |
Mistake: Using the Simple Present for an Ongoing Situation
Incorrect: I live here since 2020.
Correct: I have lived here since 2020.
In standard American English, the present perfect is normally used to express a continuing situation that began in the past with since.
Mistake: Confusing Since and Because
Example: Since it was raining, we stayed home.
Here, since expresses a reason.
It does not describe the starting point of an ongoing action.
Proofreading Checklist
- Are you describing a starting point?
- Are you describing a duration?
- Is the action ongoing or completed?
- Does the tense match the time expression?
- Are you using since to mean because?
- Are you using ago with an appropriate past-tense construction?
These questions can help prevent common mistakes.
15. Since vs For Examples and Practice Exercises
Let’s practice with everyday situations.
School 🎓
I have studied English since 2021.
I have studied English for several years.
Workplace 💼
She has worked here since January.
She has worked here for several months.
Home 🏠
We have lived in this house since 2018.
We have lived in this house for many years.
Travel ✈️
They have been traveling since Monday.
They have been traveling for three days.
Practice Quiz
Test Your Grammar0 of 10 answered
1. I have lived here ___ 2020.sincefor
2. She has worked here ___ five years.sincefor
3. We have been waiting ___ noon.sincefor
4. He studied ___ three hours.sincefor
5. They have been friends ___ childhood.sincefor
6. I have known her ___ a long time.sincefor
7. She has been reading ___ 8 AM.sincefor
8. We stayed in Florida ___ two weeks.sincefor
9. I haven’t seen her ___ Monday.sincefor
10. I moved here five years ___.agosince
16. Since vs For FAQs and Final Thoughts
Frequently Asked Questions
What is the main difference between since and for?
Since identifies a starting point. For identifies the length of time.
Can I use since with five years?
Not when five years simply means a duration. Use “for five years.” You can use since with a starting point such as “five years ago.”
Can I use for with a date?
Not when the date identifies the beginning of an ongoing period. Use since, as in “since 2020.”
Which tense is commonly used with since?
The present perfect and present perfect continuous are common when a situation began in the past and continues into the present.
Can for be used with the simple past?
Yes. For example, “I lived there for three years.”
What is the difference between since and ago?
Since identifies a starting point relative to a later time. Ago identifies how far back a past event occurred from now.
Can since mean because?
Yes. For example, “Since it was late, we went home.”
Can I use since with yesterday?
Yes. “I haven’t seen him since yesterday” is correct.
Is it correct to say for a long time?
Yes. It is a common duration expression.
Which word should I use in American English?
Use since for a starting point and for for a duration.
Final Thoughts
Understanding since vs for becomes much easier when you focus on the type of time information you want to express.
Since tells us when something began.
For tells us how long something lasted or has lasted.
Remember these two patterns:
Since + starting point
For + duration
Once you understand this difference, you can describe past experiences, ongoing situations, and everyday activities more accurately in American English.