Grammar ยท Prepositions of Time

Since vs For vs From

Three prepositions. One Hindi word (เคธเฅ‡). Thousands of wrong answers every year in SSC CGL and IBPS PO. This page fixes that permanently.

The One-Line Rule

SINCE = point in timeยทFOR = durationยทFROM = start of range (needs TO / TILL)

Side-by-Side Comparison

FeatureSINCEFORFROM
MeaningStarting point in timeLength of durationStart of a range (needs end)
FollowsPerfect tenses onlyAny tenseAny tense
Paired withNothing โ€” stands aloneNothing โ€” stands aloneTO / TILL / UNTIL
Answers"When did it start?""How long?""From when โ€” to when?"
Examplesince 2019 / since Monday / since she leftfor 5 years / for three hours / for a long timefrom 9 to 5 / from Jan to March

SINCE โ€” Point in Time

Always answers: โ€œWhen did it start?โ€

Rules:

  • 1. Always used with perfect tenses: Present Perfect, Past Perfect, Present Perfect Continuous.
  • 2. Followed by a specific point: a year (since 2019), a day (since Monday), a named event (since independence), or a clause (since she left).
  • 3. Never followed by a duration word (an hour, three days, a long time) โ€” that's FOR's job.
  • 4. Can introduce a subordinate clause: โ€œsince we were in school.โ€

โœ… Correct Examples

She has been living here since 2015.

I have not seen him since last Tuesday.

It is the best film I have seen since Lagaan.

We have been friends since we were in school.

FOR โ€” Duration

Always answers: โ€œHow long?โ€

Rules:

  • 1. Used with any tense โ€” Perfect (ongoing) or Simple (completed).
  • 2. Followed by a duration: for 5 years, for three hours, for a long time, for ages, for two weeks.
  • 3. Duration words = number + unit, or vague quantities: a long time, ages, a while, many years.
  • 4. With Perfect tense โ†’ action still ongoing. With Simple tense โ†’ action is complete.

โœ… Correct Examples

She has been studying for six hours. (still studying)

He worked there for 20 years and then retired. (completed)

I have not slept for two days.

They waited for a long time before giving up.

FROM โ€” Start of a Range

Always answers: โ€œFrom when to when?โ€ โ€” needs a paired end-point.

Rules:

  • 1. FROM must always be paired with TO, TILL, or UNTIL โ€” it cannot stand alone as a time preposition.
  • 2. Used for schedules, routines, and ranges: office hours, exam timing, historical eras.
  • 3. Used with any tense โ€” past, present, future, simple or continuous.
  • 4. Not interchangeable with SINCE in Perfect tense sentences where no end-point is given.

โœ… Correct Examples

The office is open from 9 a.m. to 6 p.m.

She studied law from 2018 to 2023.

Children learn fastest from birth to the age of five.

The exam will be held from 10 a.m. till 1 p.m.

๐Ÿ‡ฎ๐Ÿ‡ณ The Hindi โ€œเคธเฅ‡โ€ Trap โ€” Why Indian Students Get This Wrong

In Hindi/Urdu, the single postposition เคธเฅ‡ (se) covers the meanings of SINCE, FOR, and sometimes FROM. So:

Hindi โ†’ Incorrect English โ†’ Correct English

โ€œMain 2019 se yahan hunโ€ โ†’ โ€œI am here from 2019.โ€ โ†’ โ€œI have been here since 2019.โ€

โ€œMain teen ghante se wait kar raha hunโ€ โ†’ โ€œI am waiting since three hours.โ€ โ†’ โ€œI have been waiting for three hours.โ€

Fix: Translate mentally, then check โ€” is it a point in time or a duration? Point โ†’ SINCE ยท Duration โ†’ FOR.

Decision Flowchart

โ“ Which word do I use?
โ†“
Are you expressing a TIME RANGE with a clear start AND end point?
YES โ†™NO โ†˜
Use FROM โ€ฆ TO/TILL

e.g. from Monday to Friday

Is the following word/phrase a DURATION? (5 years, three hours, a long time)
YES โ†™ ย ย ย  NO โ†˜
Use FOR

+ Perfect or Simple tense

Use SINCE

+ Perfect tense only

๐ŸŽฏ The 4 Classic Exam Traps

These exact error patterns appear in SSC CGL, CHSL, and IBPS PO every year. Memorise the correction and the reason โ€” the reason is often the exam question.

Trap #1Most Common SSC Error

I have been waiting since three hours.

โœ… I have been waiting for three hours.

๐Ÿ“Œ 'Three hours' is a duration โ†’ FOR. SINCE needs a point in time, never a number + unit.

Trap #2Indian English Transfer Error

She has been working here from 2020.

โœ… She has been working here since 2020.

๐Ÿ“Œ '2020' is a year โ€” a specific starting point. In a Perfect tense sentence without a paired end-point, use SINCE, not FROM.

Trap #3Double Error Trap

He is absent since last Monday.

โœ… He has been absent since last Monday.

๐Ÿ“Œ Two errors: (1) 'is' should be 'has been' โ€” SINCE demands Perfect tense. (2) Even if (1) were fixed, SINCE is correct for 'last Monday'. Both errors together are a common Tier-I trap.

Trap #4FROM + Wrong Pair

I will work from 2 p.m. since 6 p.m.

โœ… I will work from 2 p.m. to 6 p.m.

๐Ÿ“Œ FROM pairs with TO / TILL, never with SINCE. SINCE is for starting points in perfect tense, not for giving the end of a future schedule.

๐Ÿ”‘ Examiner's Trick Box

  • โ–ธ If you see SINCE in the sentence but the following word is a number + unit (since three days, since two hours) โ€” it is always wrong. Change to FOR.
  • โ–ธ If you see FROM with a perfect tense but no end-point โ€” it is always wrong. Change to SINCE.
  • โ–ธ โ€œThe longest/best/first โ€ฆ since [event]โ€ is a fixed superlative + SINCE pattern โ€” always Present Perfect.
  • โ–ธ FOR can be used with Simple Past for completed actions. SINCE cannot. โ€œHe lived there for 5 yearsโ€ is correct. โ€œHe lived there since 2010โ€ is wrong (needs perfect tense).
  • โ–ธ โ€œSuffer FROM a diseaseโ€ โ€” here FROM is a preposition of cause, not time. Do not confuse it with the time preposition FROM. Context determines the role.