Have you ever found yourself pausing mid-sentence, unsure whether to say “I’ve been waiting since two hours” or “I’ve been waiting for two hours”? You’re not alone. These four small words—since, for, during, and while—cause confusion even among advanced English learners.
The good news? Once you understand the logic behind them, they become remarkably simple. In this guide, I’ll walk you through each preposition with crystal-clear explanations, plenty of examples, and a story-based approach that makes the rules stick. Let’s dive in.
The Big Picture: What These Words Do
All four prepositions deal with time, but they answer different questions:
| Preposition | Answers the Question | Type of Time Reference |
|---|---|---|
| SINCE | From what point? | A specific starting point |
| FOR | How long? | A duration or length |
| DURING | At what time within an event? | A named event or period (noun) |
| WHILE | At the same time as what? | An action or process (clause/gerund) |
Let’s break each one down thoroughly.
SINCE: The Starting Point Marker
Rule: Use since to refer to a specific point in time when something began. The action continues from that point until the present moment.
Grammatical structure: Since + [specific point in time]
Since always pairs with perfect tenses (present perfect, present perfect continuous, past perfect).
Examples of SINCE:
“I have lived in London since 2019.”
(2019 is the specific starting point.)
“She has been studying since six o’clock this morning.”
(Six o’clock is the exact point when she started.)
“They had known each other since childhood before they got married.”
(Childhood marks the starting point in the past.)
“We haven’t seen him since last Monday.”
(Last Monday is the specific reference point.)
“He’s been waiting since the store opened.”
(The store’s opening time is the precise moment.)
Common time expressions used with SINCE:
- since Monday / Tuesday / Friday
- since January / March / December
- since 2010 / 2015 / 2020
- since 8:00 a.m. / noon / midnight
- since I was a child
- since we moved here
- since the meeting started
- since last summer
Quick Test:
Which is correct?
- A) I’ve been here since two hours. ❌
- B) I’ve been here since 2:00 p.m. ✅
Explanation: “Two hours” is a duration, not a point. “2:00 p.m.” is a specific point.
FOR: The Duration Expresser
Rule: Use for to express a length or period of time—how long something lasts or has lasted.
Grammatical structure: For + [period/duration]
For can be used with almost any tense, not just perfect ones, though it frequently appears with perfect tenses.
Examples of FOR:
“I have been waiting for two hours.”
(Two hours is the length of time.)
“She lived in Paris for five years before returning home.”
(Five years is the duration of her stay.)
“We’re going on vacation for two weeks.”
(Two weeks expresses the length of the vacation.)
“He has been working here for a long time.”
(A long time is the period.)
“Can you hold your breath for thirty seconds?”
(Thirty seconds is the duration.)
“I’ll be away for the entire month of August.”
(The entire month expresses how long.)
Common time expressions used with FOR:
- for five minutes / two hours / three days
- for a week / a month / a year
- for a long time / ages / a while
- for the whole day / the entire night
- for centuries / decades
- for as long as I can remember
Critical Contrast: SINCE vs. FOR
Consider this pair:
| With FOR (duration) | With SINCE (point) |
|---|---|
| for ten minutes | since 3:50 p.m. |
| for three days | since Tuesday |
| for six months | since January |
| for a decade | since 2014 |
| for ages | since we last met |
“I’ve known her for fifteen years.” (length)
“I’ve known her since 2009.” (starting point)
Both sentences communicate similar information, but the grammatical framing is different. Often, you can express the same idea using either preposition:
“He’s been working here for six months.”
“He’s been working here since March.”
DURING: The Event Container
Rule: Use during to indicate that something happens within the time frame of a specific event, period, or activity. The word that follows must be a noun or noun phrase.
Grammatical structure: During + [noun / noun phrase]
Examples of DURING:
“She fell asleep during the movie.”
(The movie is the event. Her falling asleep happened at some point within that event.)
“I received several calls during the meeting.”
(The meeting is the time container for the calls.)
“He visited many countries during his trip to Europe.”
(The trip is the period containing the visits.)
“Please don’t talk during the exam.”
(The exam is the event within which talking is prohibited.)
“They met during the summer of 2022.”
(Summer 2022 is the time period.)
“The fire alarm went off during dinner.”
(Dinner is the event containing the interruption.)
“She gained a lot of experience during her internship.”
(The internship is the period of gaining experience.)
Common nouns used after DURING:
- during the day / night / weekend
- during the lesson / class / lecture
- during the flight / journey / trip
- during the war / crisis / pandemic
- during my childhood / adolescence
- during the presentation / interview / ceremony
- during breakfast / lunch / dinner
- during the storm / earthquake / blackout
Important Note:
During cannot be followed by a subject + verb clause. If you want to use a clause, you need while. This is the most common mistake learners make.
❌ “I read a book during I was waiting.”
✅ “I read a book while I was waiting.”
✅ “I read a book during my wait.”
WHILE: The Simultaneous Action Linker
Rule: Use while to connect two actions or states that happen at the same time. While must be followed by either a full clause (subject + verb) or a gerund (-ing form).
Grammatical structure: While + [subject + verb] OR While + [gerund (-ing verb)]
Examples of WHILE with a full clause:
“I listened to music while I was working.”
(Two simultaneous actions: listening and working.)
“She received a text message while she was driving.”
(Receiving and driving happened concurrently.)
“The children played outside while their parents prepared dinner.”
(Playing and preparing occurred at the same time.)
“He always eats while he watches TV.”
(Eating and watching are simultaneous habits.)
“Someone stole her wallet while she was looking at the paintings.”
(The theft occurred during the action of looking.)
Examples of WHILE with a gerund:
When the subject of both clauses is the same, we can shorten the clause by dropping the subject and using an -ing verb:
“I often listen to podcasts while driving to work.”
(= while I am driving)
“She fell while walking down the stairs.”
(= while she was walking)
“He reviewed his notes while waiting for the interview.”
(= while he was waiting)
“Try to relax while taking the test.”
(= while you are taking the test)
Critical Contrast: DURING vs. WHILE
The core difference lies in what follows the word:
| DURING + Noun | WHILE + Clause/Gerund |
|---|---|
| during the movie | while watching the movie |
| during the flight | while I was flying |
| during dinner | while eating dinner |
| during the summer | while I was on vacation |
| during her speech | while she was speaking |
| during the game | while playing the game |
“He fell asleep during the concert.” (noun)
“He fell asleep while attending the concert.” (gerund)
“He fell asleep while he was at the concert.” (clause)
All three sentences convey essentially the same event, but the structure following the preposition differs.
Learning Through Story: Marcelo in Toronto
Here’s a short narrative that incorporates all four prepositions. Reading grammar in context helps cement the rules far better than memorizing them in isolation.
Marcelo has been living in Toronto since January. He moved there for a new job opportunity. During his first week, he felt quite homesick, but things improved quickly.
He has been studying English for six months now, and he practices every day. While commuting to work on the subway, he listens to English podcasts. During his lunch break, he chats with colleagues to improve his speaking skills.
He hasn’t seen his family since he left Brazil, but he video-calls them for at least an hour every weekend. Sometimes, while talking to his mother, he gets emotional. During those moments, he reminds himself why he made this move.
Marcelo has been working at his company since March, and he’s already received praise for his dedication. While working on a major project last month, he discovered a solution that saved the team days of work. During the team meeting, his manager publicly acknowledged his contribution.
He plans to stay in Toronto for at least three more years. Since arriving, he has grown both professionally and personally. During his free time, he explores different neighborhoods, and while exploring, he often discovers hidden gems—quirky cafés, peaceful parks, and vibrant street art.
Analyzing the Story:
- SINCE marks starting points: since January, since he left Brazil, since March, since arriving
- FOR expresses duration: for a new job, for six months, for at least an hour, for his dedication, for at least three more years
- DURING introduces noun-based events: during his first week, during his lunch break, during those moments, during the team meeting, during his free time
- WHILE links simultaneous actions: while commuting, while talking, while working, while exploring
Side-by-Side Summary Table
| Preposition | Followed By | Function | Tense Commonly Used | Example |
|---|---|---|---|---|
| SINCE | Point in time (noun/clause) | Marks the start of an ongoing action | Perfect tenses | “I’ve known him since 2015.” |
| FOR | Length of time (noun phrase) | States duration | Any tense | “I waited for 30 minutes.” |
| DURING | Noun / noun phrase | Locates action within an event | Any tense | “She slept during the flight.” |
| WHILE | Clause or gerund | Connects two simultaneous actions | Any tense | “She slept while flying.” |
Common Mistakes and How to Fix Them
Mistake 1: Using “since” with a duration
❌ “I’ve been studying since three hours.”
✅ “I’ve been studying for three hours.”
✅ “I’ve been studying since 3:00 p.m.”
Mistake 2: Using “during” with a clause
❌ “It rained during we were walking.”
✅ “It rained while we were walking.”
✅ “It rained during our walk.”
Mistake 3: Using “while” with just a noun (without a gerund)
❌ “She checked her phone while the meeting.”
✅ “She checked her phone during the meeting.”
✅ “She checked her phone while attending the meeting.”
Mistake 4: Confusing “for” and “since” in present perfect sentences
❌ “He has lived here since 10 years.”
✅ “He has lived here for 10 years.”
✅ “He has lived here since 2014.”
Mistake 5: Forgetting that “during” cannot replace “while” before gerunds
❌ “I fell asleep during reading.”
✅ “I fell asleep while reading.”
✅ “I fell asleep during the reading session.”
Practice Exercises
Test your understanding. Fill in each blank with since, for, during, or while.
- I haven’t eaten anything ________ breakfast.
- The phone rang ________ I was taking a shower.
- We stayed at the beach ________ three hours.
- ________ the presentation, several people asked questions.
- She’s been much happier ________ she changed jobs.
- He injured his back ________ lifting heavy boxes.
- I’ve been a teacher ________ more than a decade.
- ________ the storm, the power went out three times.
- Please don’t interrupt ________ I’m speaking.
- They’ve known each other ________ they were in kindergarten.
Answers:
- since (breakfast = specific point)
- while (I was taking a shower = clause)
- for (three hours = duration)
- During (the presentation = noun)
- since (she changed jobs = specific point clause)
- while (lifting heavy boxes = gerund)
- for (more than a decade = duration)
- During (the storm = noun)
- while (I’m speaking = clause)
- since (they were in kindergarten = specific point clause)
Final Thoughts
These four prepositions often appear together in grammar lessons because their meanings overlap in the territory of time. The key to mastering them is remembering what grammatical structure each one requires:
- SINCE → a point in time
- FOR → a period of time
- DURING → a noun
- WHILE → a clause or gerund
If you internalize just these four structural rules, you will avoid 90% of the common errors that English learners make with these words. The next time you find yourself hesitating, ask: Am I referring to a point, a period, an event-noun, or a simultaneous action? The answer will guide you to the right preposition every time.
Do you have questions about these prepositions or other tricky grammar points? Drop a comment below—I read and respond to every one. And if you found this guide helpful, share it with a friend who’s also on their English-learning journey.
Happy learning from all of us at Advanced English Lab!
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