Since vs For: Present Perfect Time Markers Guide

Introduction

Do you ever pause mid-sentence, wondering whether to say “since Monday” or “for Monday”? You are not alone. This tiny pair of words causes confusion for even advanced English learners, yet mastering it is essential for accurate communication. In this guide, you’ll learn the simple logic behind since and for, see dozens of real examples, and test yourself with practice exercises.

What Is “Since” vs “For”?

Since and for are time markers used with the present perfect tense to talk about actions or states that started in the past and continue to the present. The key difference is simple: since points to a specific starting point, while for indicates a duration of time.

Think of it this way: since answers “When did it start?” and for answers “How long has it lasted?” This distinction is the backbone of accurate usage.

Rules

1. Use “since” with a specific point in time. This can be a date (since 2010), a day (since Monday), a time (since 3 PM), or a past event (since I moved here).
2. Use “for” with a period of time. This includes durations like years (for five years), months (for two months), weeks (for three weeks), or hours (for two hours).
3. Always use the present perfect (have/has + past participle) with both. Example: “I have lived here since 2015” and “I have lived here for six years.”
4. Never use “since” with a duration. Saying “since two years” is incorrect; you must say “for two years.”
5. Never use “for” with a specific starting point. Saying “for Monday” is incorrect; you must say “since Monday.”
6. “Since” can also introduce a clause. For example: “She has been happy since she found a new job.” Here, “since” is followed by a full clause (subject + verb).
7. “For” is often omitted in short answers. “How long have you worked here?” — “For three years” or simply “Three years.” Both are fine.
8. Use “since” with “ever” for emphasis. “He has been my best friend ever since we were kids.” This adds emotional weight.

How to Use It

Follow these simple steps to choose correctly every time:

1. Identify the time expression. Look at the words after the blank. Is it a specific moment or a duration?
2. Ask yourself: “Can I put a clock or calendar on it?” If yes, it’s a starting point → use since. For example, “2 o’clock,” “January,” “my birthday.”
3. Ask yourself: “Does it describe a length?” If yes, it’s a duration → use for. For example, “two hours,” “a decade,” “a while.”
4. Check the verb form. Ensure you use the present perfect: have/has + past participle. For irregular verbs, memorize the past participle (e.g., go → gone, see → seen).
5. Test with a question. If you can ask “Since when?” → use since. If you can ask “How long?” → use for. This trick works in most cases.

Example: “I have studied English since 2018.” (Since when? 2018 — a starting point.) “I have studied English for five years.” (How long? Five years — a duration.)

Examples in Sentences

• We have known each other since we were children.
• She has worked at this company for ten years.
• I haven’t seen that movie since last summer.
• They have been married for over twenty years.
• He has been feeling sick since Tuesday.
• My brother has played the guitar for four years.
• We have lived in this neighborhood since 2019.
• The store has been open for eight hours.
• I have loved reading since I was a child.
• She has owned that car for a long time.
• They have been waiting since 9 AM for the bus.
• He has practiced the piano for thirty minutes every day.

Common Mistakes

• ❌ I have been learning English since three years.
  ✅ I have been learning English for three years.
  Reason: “three years” is a duration, not a starting point.
• ❌ She has lived here for 2015.
  ✅ She has lived here since 2015.
  Reason: “2015” is a specific year — a starting point.
• ❌ They have been friends since a long time.
  ✅ They have been friends for a long time.
  Reason: “a long time” describes a length, not a point.
• ❌ He has worked here since two months.
  ✅ He has worked here for two months.
  Reason: “two months” indicates duration.
• ❌ I haven’t eaten anything for this morning.
  ✅ I haven’t eaten anything since this morning.
  Reason: “this morning” is a specific time reference.

Quick Summary

• Since = starting point (a specific time, date, or event).
• For = duration (a length of time).
• Both are used with the present perfect tense.
• Ask “Since when?” → use since.
• Ask “How long?” → use for.
• Never mix them up: “since two years” and “for Monday” are both incorrect.
• Remember: since + point, for + period.

Practice Exercises

Fill in the blanks with either since or for:

1. I have been a teacher __________ 2012.
2. They have known each other __________ five years.
3. She has been tired __________ this morning.
4. We have lived in Madrid __________ six months.
5. He has played soccer __________ he was a teenager.

Answers:

1. since (2012 is a specific year)
2. for (five years is a duration)
3. since (this morning is a specific time)
4. for (six months is a duration)
5. since (he was a teenager is a starting point)

Conclusion

Mastering since vs for is a small change that makes a huge difference in your English accuracy. Remember the golden rule: since for starting points, for for durations. Practice daily, and soon you’ll use them without thinking. Keep learning, and don’t forget to check out more grammar guides on EnglishGrammarZone.com!

FAQ

1. Can I use “since” with the past simple tense?

Yes, but the meaning changes. “Since” can be used with past simple in sentences like “It has been two years since I saw him.” Here, “since” introduces a past event, but the main clause uses the present perfect. You cannot say “I lived here since 2010” — that’s incorrect because the present perfect is required for the ongoing state.

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

“From” is used to indicate a starting point but usually pairs with “to” or “until” and works with any tense. For example: “I work from 9 to 5.” “Since” is specifically used with the present perfect to show that the action continues to now. You cannot say “I work here since 2010” — you must say “I have worked here since 2010.”

3. Can “for” be used with other tenses?

Absolutely. “For” can be used with any tense to indicate duration. For example: past simple (“I lived there for two years”), present simple (“I walk for an hour daily”), and future (“I will study for three hours”). However, when using the present perfect, “for” shows that the duration continues to the present.

4. Is it ever correct to say “since” with a duration?

No, never. “Since” must always be followed by a specific point in time. If you want to express a duration, use “for.” Some learners make this mistake because their native language uses one word for both. Stick to the rule: since + point, for + period.