Grammar basics
Prepositions of time
A preposition of time tells you when something happens: at 5 p.m., on Monday, in July, before work.
In, on, at
| Word | Use it for | Examples |
|---|---|---|
| at | exact times | at 5 p.m., at noon, at night |
| on | days and dates | on Monday, on July 4, on my birthday |
| in | longer times | in July, in 2026, in the morning |
The In, On and At cards are on the Prepositions page. This page has more time words.
For or since?
| Word | Use it with | Example |
|---|---|---|
| for | an amount of time | I have lived here for five years. |
| since | a starting point | I have lived here since 2021. |
Common mistake
Thai uses ตั้งแต่ for since and เป็นเวลา for for. Many learners say I have studied English since two years. Two years is an amount of time, so say for two years.
Before
Earlier than something.
I drink coffee before work.
After
Later than something.
Let's go for a walk after lunch.
During
From the start to the end of something.
Please turn off your phone during the meeting.
For
Shows how long something happens.
I studied English for two hours today.
Since
From a time in the past until now.
I have lived in Bangkok since 2020.
Until
Up to a certain time, and then stop.
I work from 9 a.m. until 6 p.m.