once a year
fixed phr.. A1 Beginner Oxford
fixed phr.. This means something happens one time every year.
fixed phr.. An adverbial phrase of frequency indicating that an event occurs one time per annum.
We visit my grandma once a year.
The special town festival happens once a year in the summer.
The audit, which takes place once a year, scrutinizes every aspect of the company's financial records.
Usage
This phrase usually appears at the end of a sentence to describe how often an action occurs.
Teaching tip
Contrast with the more formal single-word adverb 'annually' and other frequency phrases like 'twice a year' or 'every other year'.
Pitfall
I see my cousins once year.I see my cousins once a year.The indefinite article 'a' is required between 'once' and the time period 'year'.