Sex is biological (male or female) while gender has connotations of upbringing and choice (feminine or masculine). People can choose which gender to be, irrespective of their biological sex.
Always use the word “sex” except for the following:
- specifically discussing people’s gender (social construct) as opposed to their sex (biological)
- you are reporting on a survey that specifically asked about “gender” rather than “sex”
- commonly used and recognised terms, such as “gender pay gap”
There are two sexes that children can be born into: male and female.
The “gender pay gap” has decreased over the last five years.
Man or men and woman or women
A population made up of only adult males should be described as “men”. If it includes children, use “males”. If it is only children, use “boys”.
The over-18 football team was a group of men.
The football team was a group of males.
The under-10s football team was a group of boys.
A population that is made up of adult women only should be described as “women”. If it includes children, use “females”. If it is children only, use “girls”.
The over-18 football team was a group of women.
The football team was a group of females.
The under-10s football team was a group of girls.