The Ultimate Guide to ‘For’ and ‘Since’: Finally Mastering the Perfect Tenses

Picture this: You’re catching up with a new English-speaking friend, and they ask you about your life. “How long have you been in this city?” they ask. You feel confident. You know the answer. You open your mouth and say, “I am living here since five years.”

Your friend nods, understanding what you mean, but something in their expression flickers. The sentence, though understandable, sounds slightly off, like a musical note played just out of key. It’s a tiny error, but it’s a clear signal to a native speaker that you are still translating in your head.

Welcome to the world of ‘for’ and ‘since’. These two small, seemingly simple words are responsible for some of the most common and persistent grammar mistakes among English language learners. They are the gatekeepers to the perfect tenses and the key to speaking about time with natural, native-like fluency.

Many learners find them endlessly confusing. The rules can seem arbitrary, and the connection to specific verb tenses feels complex. But what if we told you that by the end of this article, this confusion could be a thing of the past?

This is not just another quick explanation. This is your ultimate guide, your definitive masterclass on ‘for’ and ‘since’. We will go beyond the basic rules to explore the deep connection these words have with verb tenses, dissect common errors, answer frequently asked questions, and provide you with dozens of examples and a practice quiz to solidify your knowledge. Our goal is for this to be the last guide you will ever need on the topic.

By mastering these two little words, you will take one of the biggest leaps forward in your English journey, moving from someone who simply communicates information to someone who expresses themselves with grammatical precision and confidence.

Part 1: The Golden Rule – Duration vs. Starting Point

Before we can talk about any verb tense, we must understand the fundamental, unshakable difference between ‘for’ and ‘since’. If you remember nothing else, remember this:

• FOR is used to talk about a duration of time. It answers the question, “How long?”
• SINCE is used to talk about a starting point in time. It answers the question, “Starting when?”

Let’s visualize this with an analogy.

Imagine time is a long ruler. FOR is like using the ruler to measure a specific length or distance. It doesn’t matter where on the ruler the measurement starts or ends; what matters is the length itself.

• A length of ten centimetres. -> for ten seconds.
• A length of five kilometres. -> for five months.

Now, imagine time is a calendar. SINCE is like pointing to a single, specific date on that calendar. It’s not a measurement of length; it is a fixed point from which we begin counting.

• This specific date: June 19th. -> since Monday.
• This specific year: 1999. -> since 1999.

Let’s break this down with extensive examples to make it crystal clear.

Use FOR with a period or duration of time:

• for ten seconds
• for thirty minutes
• for two hours
• for six days
• for three weeks
• for five months
• for eight years
• for two decades
• for a century
• for a long time
• for ages
• for a little while

Notice that all of these phrases represent a quantity or length of time.

Use SINCE with a specific point or moment in time:

• since 9:00 AM
• since noon
• since yesterday
• since Wednesday
• since last week
• since February
• since 2020
• since the 1980s
• since my birthday
• since I was a child
• since the meeting ended
• since the beginning of time

Notice that all of these phrases represent a starting pistol—a single moment when the clock began ticking. You can’t put a number before these phrases (you can’t say “for yesterday” or “for my birthday”).

This core distinction is the foundation upon which everything else is built.

Part 2: The Perfect Partnership – ‘For’/’Since’ and the Present Perfect Tense

Here we arrive at the heart of the matter and the source of most mistakes. The Golden Rule above is simple enough, but the reason it gets confusing is its intimate relationship with the Present Perfect Tense.

The Present Perfect (formed with have/has + past participle) is a verb tense that acts as a bridge, connecting the past with the present. It is used to talk about an action or state that began in the past and is still true or continues up to now.

This is precisely what ‘for’ and ‘since’ do. They anchor a continuous past action to the present moment. This is why they are so often used together.

Let’s dissect the common error from our introduction: Incorrect: “I am living here for five years.”

The problem here is a tense conflict. The Present Continuous (“am living”) describes an action happening right now, at this very second. But the phrase “for five years” describes a duration that stretches back into the past. The two ideas clash. You need a tense that bridges the past and present. That tense is the Present Perfect.

Correct: “I have lived here for five years.”

This sentence beautifully connects the past and the present. It tells us the action of living here started five years ago and—this is the crucial part—it is still happening now.

The formula is simple:

Subject + have/has + Past Participle … for + [duration] Subject + have/has + Past Participle … since + [starting point]

Let’s build our confidence with a bank of clear examples:

• Situation: She started her job 3 years ago and still works there.

  • She has worked here for three years.
  • She has worked here since 2022.

• Situation: They got their dog a long time ago and still have him.

  • They have had their dog for a long time.
  • They have had their dog since he was a puppy.

• Situation: I stopped smoking on January 1st and I haven’t smoked again.

  • I haven’t smoked for over six months.
  • I haven’t smoked since January.

• Situation: He started feeling unwell on Monday and still feels unwell.

  • He has been sick for several days.
  • He has been sick since Monday.

Mastering the Present Perfect tense is one of the biggest steps you can take toward sounding truly fluent in English. It’s a concept that doesn’t exist in many other languages, which is why it can be so tricky. It’s a core focus in our intermediate courses at NLS, where we use real-world conversations and exercises to make it feel natural. Learn more about how we can help you master this crucial grammar point: https://nlsnorwegian.no/learn-english/

Part 3: Expanding the Rules – Other Tenses and Advanced Contexts

While the Present Perfect is the most common partner for ‘for’ and ‘since’, the rules are more flexible than you might think. Understanding how these words interact with other tenses will elevate your English to an advanced level.

Using ‘For’ with the Past Simple You can absolutely use ‘for’ with the Past Simple tense (e.g., lived, worked, was), but it completely changes the meaning of the sentence. It signals that the action is finished and has no connection to the present.

Let’s compare directly:

• Present Perfect: “She has lived in London for ten years.”
  • Meaning: She started living in London ten years ago, and she still lives in London now. The action continues.
• Past Simple: “She lived in London for ten years.”
  • Meaning: She spent a duration of ten years living in London at some point in the past, but the action is finished. She does not live in London now.

This is a critical distinction for clear communication. If you say, “I have worked at my company for three years,” it means you are still an employee. If you say, “I worked at my company for three years,” it means you have quit that job.

Using ‘Since’ – The Perfect Tense’s Best Friend ‘Since’ is much more restrictive. Because its entire job is to create a bridge from a past point to a later point (usually the present), it is almost exclusively used with Perfect Tenses (Present Perfect, Past Perfect, etc.).

• Correct: “He has been a vegetarian since 2010.”
• Incorrect: “He was a vegetarian since 2010.”

Using ‘Since’ as a Conjunction To add another layer, ‘since’ can also act as a conjunction, connecting two parts of a sentence. In this form, it can have two meanings:

1. Meaning ‘because’: This is a more formal way to say ‘because’.

   • “Since you are already here, you might as well help me with these boxes.”
   • “I decided to walk since it was such a beautiful day.”

2. Connecting a past event to the present: In this structure, the clause after ‘since’ is in the past simple and acts as the “starting point.”

   • “She has become much more confident since she started the English course.” (The starting point was the moment she started the course).
   • “I haven’t seen him since he moved to another city.” (The starting point of not seeing him was the moment he moved).

Part 4: Common Questions, Mistakes, and a Practice Quiz

Let’s tackle some common areas of confusion head-on.

Frequently Asked Questions (FAQ)

• Q: What’s the difference between ‘during’ and ‘for’?

  • A: This is a great question. ‘For’ answers “How long?” (a duration). ‘During’ answers “When?” (within a specific named period). Compare: “He slept for two hours.” (Duration). “He slept during the movie.” (When?).

• Q: Can I use ‘from’ instead of ‘since’?

  • A: Sometimes, but be careful. ‘From’ is usually paired with ‘to’ or ‘until’ to show a finished period in the past. “I worked there from 2018 to 2021.” You use ‘since’ when the action continues to the present.

• Q: What about “ago”? How is it different?

  • A: “Ago” is used with the Past Simple to say when something finished happened, counting back from the present. “I finished the project three weeks ago.” (The action is over). Compare: “I have been working on this project for three weeks.” (I am still working on it).

Practice Quiz: For or Since? Test your knowledge! Fill in the blanks with the correct word. The answers are at the bottom.

1. She has been waiting for the bus ______ twenty minutes.
2. I haven’t eaten anything ______ breakfast.
3. My family has lived in this house ______ 1995.
4. He worked as a teacher ______ ten years before he retired.
5. We have been planning this trip ______ a long time.
6. They have been best friends ______ they were in primary school.
7. The baby has been crying ______ the last hour.
8. I haven’t visited my grandparents ______ last Christmas.
9. He will be on vacation ______ three weeks.
10. It has been raining nonstop ______ yesterday afternoon.

Did you get them all right? Self-study is a great start, but getting instant, personalized feedback from a professional teacher is the fastest way to identify and correct these ingrained mistakes. A teacher can hear your errors and give you targeted exercises to fix them. Learn more about our interactive classes: https://nlsnorwegian.no/learn-english/

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(Quiz Answers: 1. for, 2. since, 3. since, 4. for, 5. for, 6. since, 7. for, 8. since, 9. for, 10. since)

Conclusion: From Confusion to Complete Confidence

We have taken a deep dive into the world of ‘for’ and ‘since’, from the golden rule of duration vs. starting point to their crucial partnership with the perfect tenses and their use in more advanced contexts.

It may seem like a lot to remember, but it all boils down to a few key ideas:

• FOR measures a duration (How long?).
• SINCE pinpoints a starting time (Starting when?).
• When an action starts in the past and continues to the present, you must use the Present Perfect Tense (“I have lived…”) to bridge the past and the present.

Mastering these two small but mighty words will have an outsized impact on your English. It will clean up your grammar, make your speech sound more natural, and boost your confidence in your ability to express yourself accurately.

The journey from confusion to confidence is a process of learning, practicing, making mistakes, and learning again. Each time you consciously choose the right word, you are building a stronger, more intuitive understanding of the language.

Don’t let these small words cause big problems in your English communication. Take the lessons from this guide and start applying them today.

Ready to move beyond rules on a page and into active, confident conversation? Our courses are designed to turn this kind of knowledge into practical, real-world skill. We invite you to join us and take the next decisive step on your path to fluency.

Master the details and speak with confidence. Register for an English course at NLS today and make these rules second nature: https://nlsnorwegian.no/learn-english/