ESL Grammar: Prepositions - Prepositions of Time, In, On, At, For, Since, Ago

What It Is

Prepositions of Time are words that show when something happens or started. They can be tricky because there are many different options, and the correct one depends on the situation. For example, "I'm going to the store at 5 o'clock" is correct, but "I'm going in the store at 5 o'clock" is not. This topic causes difficulty for ESL learners because their first language may use different words or word orders to express time.

Key Rules

• In is used for inside a place or a period of time: "I'm in the store" or "I've been in the store for an hour."
• On is used for days, dates, and months: "I'm going to the store on Monday" or "My birthday is on January 1st."
• At is used for specific times: "I'm going to the store at 5 o'clock" or "The meeting is at 2 PM."
• For is used for periods of time: "I've been studying English for three years" or "I'll be on vacation for two weeks."
• Since is used for starting a period of time: "I've been studying English since 2018" or "I've been working here since last year."
• Ago is used for a period of time in the past: "I haven't seen my friend since ago" or "I was born 20 years ago."
• In can also be used for a period of time in the past: "I've been studying English in 2018" or "I was born in 2006."
• On can also be used for a specific day in the past: "I went to the store on Monday last week" or "I was born on January 1st last year."
• At can also be used for a specific time in the past: "I was at the store at 5 o'clock yesterday" or "I was born at 2 PM."
• For can also be used for a period of time in the past: "I've been studying English for three years" or "I was working here for two years."
• Since can also be used for a period of time in the past: "I've been studying English since 2018" or "I was working here since last year."
• Ago can also be used for a period of time in the past: "I haven't seen my friend since ago" or "I was born 20 years ago."
• The order of adjectives is important: "I'm going to the big red store" or "I'm going to the store that is big and red."
• Yesterday, today, and tomorrow are used for days in the past, present, and future: "I went to the store yesterday" or "I'm going to the store tomorrow."
• Last week, last month, and last year are used for periods of time in the past: "I went to the store last week" or "I was working here last year."
• Next week, next month, and next year are used for periods of time in the future: "I'm going to the store next week" or "I'll be working here next year."

Common ESL Errors

• Error: "I'm going in the store at 5 o'clock."
• Why it happens: Interference from L1, where "in" is used for inside a place.
• Correction: "I'm going to the store at 5 o'clock" (use "to" for going to a place).
• Error: "I've been studying English on 2018."
• Why it happens: Overgeneralization of "on" for dates.
• Correction: "I've been studying English since 2018" (use "since" for starting a period of time).
• Error: "I was born at 2 PM yesterday."
• Why it happens: Overgeneralization of "at" for specific times.
• Correction: "I was born at 2 PM" (use "at" for specific times, not for yesterday).

Practice Exercises

1. Fill in the blank: "I'm going to the store ______ (be) open at 9 o'clock." Answer: "I'm going to the store to be open at 9 o'clock." Reason: Use "to" for going to a place.
2. Fill in the blank: "I've been studying English ______ (be) three years." Answer: "I've been studying English for three years." Reason: Use "for" for periods of time.
3. Fill in the blank: "I'm going to the store ______ (be) closed yesterday." Answer: "I'm going to the store to be closed yesterday." Reason: Use "to" for going to a place.

Last-Minute Revision

Yesterday, today, and tomorrow are used for days in the past, present, and future.
Last week, last month, and last year are used for periods of time in the past.
Next week, next month, and next year are used for periods of time in the future.
In is used for inside a place or a period of time.
On is used for days, dates, and months.
At is used for specific times.
For is used for periods of time.
Since is used for starting a period of time.
Ago is used for a period of time in the past.
To is used for going to a place.
Been is used for periods of time in the past.
Been is used for periods of time in the present.