Ah, the present perfect tense—a grammar marvel that allows us to talk about actions or states that began in the past and are still relevant now. But wait! Along with the present perfect come two little words that can be tricky to master: “for” and “since”. While they both help us talk about time, they have very different jobs.
In this guide, we’ll break down the difference between “for” and “since”, show you how to use them with the present perfect tense, and give you practical tips to keep things clear. By the end, you’ll be confidently talking about how long you’ve been doing something (or since when!) like a pro.
1. Present Perfect Tense: A Quick Refresher
Before diving into the “for” and “since” showdown, let’s quickly review the present perfect tense. We use this tense to talk about actions that started in the past but are still connected to the present.
Form:
- Subject + has/have + past participle
Examples:
- I have lived in this city for five years.
- She has worked at that company since 2010.
See how those actions began in the past but are still true now? That’s where “for” and “since” come in. They tell us how long something has been happening or when it started!
2. “For”: Measuring Time in Blocks
Use “for” when you want to talk about the duration of time—how long something has been going on. Think of “for” as your way to measure chunks of time, like hours, days, months, or even years.
Examples:
- I have known him for five years.
(The action of knowing started five years ago and continues now.) - They have been married for ten years.
(They started being married ten years ago, and they still are!)
Common Time Phrases with “For”:
- For two hours
- For three days
- For a long time
- For ten years
Practical Tip:
If you can answer the question “how long?” with a block of time, you should use “for”.
3. “Since”: Pinpointing the Start
Use “since” when you want to specify the starting point of an action or event. “Since” is your way of telling people when something began. Unlike “for,” which measures time, “since” marks the moment it all started.
Examples:
- I have worked here since 2018.
(The action of working started in 2018 and continues now.) - She has lived in London since she was a child.
(She started living in London when she was a child, and she’s still there.)
Common Time Phrases with “Since”:
- Since last year
- Since 9 o’clock
- Since Monday
- Since childhood
Practical Tip:
If you can answer the question “since when?” or “from which time?” with a specific starting point, use “since”.
4. Key Differences Between “For” and “Since”
Now, let’s sum up the key differences:
- “For” is used to talk about the duration of time (how long something has been happening).
- Example: I have lived here for five years.
(Five years is the block of time.)
- Example: I have lived here for five years.
- “Since” is used to talk about the starting point (when the action or event began).
- Example: I have lived here since 2017.
(2017 is the specific moment the action started.)
- Example: I have lived here since 2017.
5. Common Mistakes with “For” and “Since”
Even though the difference seems clear, ESL learners often make a few common mistakes with “for” and “since.” Here’s how to avoid them!
Mistake #1: Using “For” with a Specific Time
Remember, “for” is for duration. It can’t be used with a specific starting point.
- Incorrect: I have worked here for 2010.
- Correct: I have worked here since 2010.
Tip: If you’re giving a specific time (like a date or year), use “since”.
Mistake #2: Using “Since” with a Duration
“Since” is for the starting point, not for how long something has been happening.
- Incorrect: I have known her since five years.
- Correct: I have known her for five years.
Tip: If you’re describing how long something has been happening, use “for”.
Mistake #3: Forgetting to Use Present Perfect with “For” and “Since”
Both “for” and “since” are used with the present perfect tense, not the simple past.
- Incorrect: I lived here for five years.
- Correct: I have lived here for five years.
Tip: When you use “for” or “since” to talk about actions that are still true, make sure you’re using the present perfect tense.
6. Quick Recap Table: “For” vs. “Since” at a Glance
| Word | Use | Example |
|---|---|---|
| For | Duration of time (how long?) | I have lived here for five years. |
| Since | Starting point (since when?) | I have lived here since 2017. |
Conclusion: Time’s Up—You’ve Mastered “For” and “Since”!
By now, you’re ready to talk about how long things have been happening and when they started with confidence. Whether you’ve been studying English for three months or you’ve been hooked on learning grammar since your first class, you can now use “for” and “since” like a native speaker.
Remember:
- Use “for” when talking about duration.
- Use “since” when talking about a starting point.
- Always pair them with the present perfect tense!