Time-based prepositions can often cause problems, and the question in the title is one I often get asked. The answer is simple: on the weekend is from American English, whereas at the weekend is British English. Whatever you do, though, don’t say in the weekend. That’s wrong on either side of the Atlantic!
On/at the weekend is an adverbial phrase, so it’s positioning in a sentence is flexible. Let’s look at the following example:
- I watch TV.
This is a simple sentence, with a subject (I), a verb (watch), and an object (TV). Now let’s add our adverbial phrase:
- At the weekend, I watch TV.
- I watch TV at the weekend.
Both sentences are grammatically correct, but in normal conversation, the second sentence is more common. Time adverbs usually go at the end of a sentence, but we can put them at the beginning if we want to emphasise the adverb.
The above examples could be used for one specific weekend (“At the weekend, I went to Hong Kong.”), or it could be used to talk about a regular occurrence (“I normally play soccer at the weekend.”). If you want to explicitly talk about a regular occurrence, take the out of the phrase and pluralise weekend:
- On weekends, I watch TV.
- I watch TV on weekends.
Note that in both the singular and plural versions, when the phrase is at the beginning of the sentence, I have used a comma. This is a style choice, i.e. some publishers and universities encourage it, while others don’t. There are many style guides that wouldn’t include a comma. When taking the IELTS exam, you can use any commonly-used style guide. Just make sure you’re consistent! Therefore, you can correctly write:
- On the weekend I watch TV.
- On weekends I watch TV.
Lastly, when the phrase comes at the end of the sentence, a comma is never used.