"working as a trainee" is a correct and usable phrase in written English.
It can be used to describe a person's current job or role as a trainee in a particular field. Example: After graduating from college, I started working as a trainee at a law firm to gain practical experience before becoming a fully-fledged lawyer.
Back in his home town of Manchester, he spent a year working as a trainee actuary.
Career After working as a trainee architect, cameraman, photocopier salesman and debt collector, he opened his first restaurant, The Fat Duck at Bray, Berkshire, in 1995.
Exactly what kind of food business was shaped by three months she spent working as a trainee chef at Gauthier Soho, for research ("for the first month I was mostly dicing aubergines, grating parmesan, and trimming asparagus").
A couple of years ago, he spent 6 months working as a trainee in ESA's Crew Medical Support Office in the European Astronaut Centre in Cologne, Germany.
When you first start working as a trainee patent attorney, you are primarily involved in securing patent protection in Australia for overseas clients, under the supervision of a senior attorney in the firm.
Two months earlier, I had arrived in Strasbourg, France, with my physics diploma tucked into a blue leather suitcase, and a letter that said I was working as a trainee for the European Science Foundation, an organization that co-ordinates research in Europe on behalf of 76 national research agencies and academies.
He then worked as a reporter trainee at The Times but gave up a career in journalism to work for an advertising agency as a copywriter.
McGregor once worked as a trainee plumber.
In 1927, she went to work as a trainee at Kurt Wolff Verlag in Munich.
I only got interested when my then girlfriend, a film editor, suggested I should work as a trainee editor during the long university holidays.
He'd just returned from Trephina Gorge, where he worked as a trainee ranger and was singing and clapping to his favourite tunes before a beery night out.
