Since vs For: Fix This in Five Minutes

Here is a sentence I hear every single week: "I have been learning English since three years."

If you say this, I have good news and better news. The good news: everyone understands you. Nobody is confused. The better news: this mistake has one of the easiest fixes in all of English. Most grammar problems need weeks of practice. This one needs five minutes and one question.

I've been teaching English for over five years. In that time, I've probably corrected since and for a thousand times. And I've noticed something. Students don't get this wrong because it's hard. They get it wrong because nobody gave them the short version. Teachers explain it with timelines and long definitions, and the simple trick gets lost.

So today, no timeline. No long definitions. One question, a few examples, and you're done. Forever, hopefully.

01 · The Big Idea

The Big Idea

Here is the whole rule:

That's it. Print it on a t-shirt.

Since answers the question "when did it start?" It points at one moment on the calendar or the clock:

• I've lived here since 2020.
• She's been at work since 8am.
• We've been friends since university.

For answers the question "how long?" It measures an amount of time:

• I've lived here for four years.
• She's been at work for six hours.
• We've been friends for fifteen years.

Look at those pairs. Same facts. Same people. The only difference is how we describe the time. A starting point, or a length.

So "since three years" fails because three years is not a point. It's an amount. You can't point at "three years" on a calendar. You can point at 2023. That's the entire problem, and now you know it.

02 · The One-Second Test

The One-Second Test

When you're speaking and you're not sure, ask this:

If yes, it's a point. Use since.

• Monday? On the calendar. Since Monday.
• 6 o'clock? On the clock. Since 6 o'clock.
• My birthday? On the calendar. Since my birthday.
• Christmas? Calendar. Since Christmas.

If no, it's an amount. Use for.

• Two hours? Not on a clock. That's an amount. For two hours.
• Ten minutes? Amount. For ten minutes.
• A long time? Definitely an amount. For a long time.
• Ages? Amount (and a nice natural word). For ages.

One second. One question. Done.

03 · Examples From Real Life

Examples From Real Life

Example 1: Sleep.

• The baby has been asleep since 7pm. (Point. You can see 7pm on a clock.)
• The baby has been asleep for three hours. (Amount. Enjoy the silence.)

Example 2: Weather.

• It's been raining since Tuesday. (Point.)
• It's been raining for five days. (Amount. Time to buy better shoes.)

Example 3: Work.

• I've worked here since January. (Point.)
• I've worked here for six months. (Amount.)

Example 4: Coffee.

• I haven't had coffee since this morning. (Point. A sad point.)
• I haven't had coffee for seven hours. (Amount. An emergency.)

Notice something about all these sentences. They use the present perfect (have worked, has been, haven't had). That's not an accident. Since and for love the present perfect, because these sentences describe something that started in the past and continues now. I've written a whole post about that tense. But you don't need it to use today's rule. The point-or-amount question works on its own.

04 · Memory Tricks

Memory Tricks

Trick 1: SINCE = START

Both words begin with S. Since points at the start. If you remember nothing else, remember this pair. Since, start. Two seconds of your life, saved forever.

Trick 2: FOR = a number, usually

Look at the for examples again. For two hours. For ten minutes. For six months. For fifteen years. Most for phrases have a number in them. Not all (for ages, for a while), but most. If you hear a number of hours, days, or years, your brain should whisper for.

Trick 3: Learn the chunks, not the rule

Here's the honest teacher secret. Native speakers don't use a rule for this. They've simply heard since Monday and for two hours so many times that the wrong version sounds broken to them. You can build the same feeling. Don't just learn the rule. Learn full chunks: since I was a child, for a long time, since last year, for a few days. Say them out loud a few times. After enough repetitions, "since three years" will sound wrong to you too. That's the goal. Not knowing the rule. Feeling it.

05 · One Small Extra (Then We Stop)

One Small Extra (Then We Stop)

Since has a second job. It can also mean because:

• Since you're here, can you help me?

Don't panic about this. The meaning is always clear from the sentence. Nobody has ever heard "since you're here" and thought it was about time. I mention it only so you don't get confused when you see it in a book.

Also, sometimes English drops for completely: "I've lived here ten years" is fine in conversation. Dropping since is not allowed. "I've lived here 2020" sounds like your sentence fell down the stairs. So when in doubt, keep both words in.

That's all the nuance you need. Really.

06 · Common Mistakes

Common Mistakes

Mistake 1: "Since three years." The classic. Three years is an amount, so it's for three years. If you want since, give the starting year: since 2023.

Mistake 2: "For 2019." The same mistake, backwards. 2019 is a point on the calendar. Since 2019.

Mistake 3: "I am here since Monday." The words are right, but the tense is wrong. With since and for, use the present perfect: I have been here since Monday. Many languages use the present tense here, so this mistake usually comes from translating. Don't feel bad. Just learn the English chunk as one piece: I've been here since...

Mistake 4: "During three years." During is a nice word, but it answers "when?", not "how long?". For length, English wants for: I studied French for three years.

Be kind to yourself with these. They're some of the most common mistakes in the world, made by millions of smart people every day. You're just the one fixing it today.

07 · Try This Today

Try This Today

Five quick questions. Since or for? Answers at the bottom.

1. I've had this phone _______ two years. 2. She's been vegetarian _______ 2021. 3. We've been waiting _______ forty minutes. 4. He hasn't called me _______ my birthday. 5. They've known each other _______ ages.

And one action step. Today, say one true sentence about your own life using each word. Out loud. For example: "I've lived in my city since 2015. I've lived there for nine years." Your own life, your own numbers. Sentences about you stick better than sentences about anyone else.

08 · Five Minutes, As Promised

Five Minutes, As Promised

Back to that sentence from the start: "I have been learning English since three years." You now know exactly why it's wrong, and you can fix it in your sleep. Three years is an amount. For three years. The start was 2023. Since 2023.

Here's the bigger lesson hiding inside this small one. This mistake survived in your English for years, not because it was hard, but because nobody made you practise the fix until it was automatic. Understanding took five minutes. Now give it five more repetitions this week, and it's yours for life.

Small rule. Small practice. Permanent result. That's how this whole language thing actually works.

Answers: 1. for 2. since 3. for 4. since 5. for

WordCat turns small rules like this one into chunks you review until they're automatic, a few minutes a day. Try it at wordcat.app.