There are no rules, I'm afraid, although a number of patterns emerge. Unskilled or semi-skilled job-holders are often denoted with …er, whilst those in scientific or medical professions are often designated with …ist. But there are many exceptions.

The …er suffix is very common, but so is …or. The …ist ending is also quite common, but so is …an. We also have …ant (accountant, shop assistant, civil servant, flight attendant) …man (postman, fireman, dustman, barman, draughtsman, fisherman), …ess (waitress, hostess, Headmistress) …ee (trainee, employee) and …ive (representative, machine operative), etc.

It is really a matter of leaning them and knowing them. Learn them in word families, as in these examples below.

…er (but not only …er)

• Bob's a well-known local builder who employs two plumbers, three carpenters, a roofer, four electricians and half a dozen unskilled labourers.
  
  
• If teachers, education officers, child minders and social workers had worked together, none of these children would have suffered abuse.
  
  
• He's a writer - the author of four books about China, but he's also worked as a translator and interpreter, actor
  and journalist.

…or (but not only …or)

• The Managing Director delegated responsibility for the project to the supervisor, but he was a poor administrator and would never become a manager.

Note that noun and verb forms relating to common occupations ending in …er and …or are closely linked: teachers teach, writers write, actors act, supervisors supervise, directors direct, bus and truck drivers drive their buses and lorries, sailors sail, etc.

Note also that the …er /…or suffixes are also used for machines and equipment that do a particular job:

• My kitchen is full of the latest gadgets: dishwasher, gas cooker with five burners, electric toaster, electric can opener, blender / liquidiser - you name it, I've got it.
  
  
• My son's got all his stuff in his bedroom: DVD player, video recorder, camcorder, film projector.
  

…ist (but not only …ist)

• The whole family are musicians: Ed's a percussionist and pianist, Viola's a flautist and cellist and Barry's a French horn player. Their parents are both singers.
  
  
• He's a doctor - a general practitioner, but he wants to become a specialist - a gynaecologist and obstetrician.
  
  
• His older sister's a chemist / pharmacist, his younger sister's a speech therapist and his mother works as his receptionist and telephonist.
  

…an (both …ian and …man)

• Did you say you were an optician? ~ No, I'm a politician. I'm spokesman for international affairs and chairman of the refugee committee. My older brother is the parliamentary librarian. My younger brother's a magician.

In the above example, …man can refer to both men or women. Some people now argue that using …man is sexist and prefer to use spokesperson or chairperson. We obviously do not have the same problem with policeman and policewoman, although if we don't wish to specify the sex of the person, we can use police officer instead.

- suffix (but not only - suffix)

Note that there are a number of jobs and professions which do not have suffixes such as those outlined above. Here are a few of the most common:

• In the Roman Catholic Church, bishops are senior to priests and in the Anglican Church rectors normally have wider responsibilities than vicars and curates.
• She's a nurse on a hospital ward but hopes to be promoted to sister and matron one day.
  
• He's pastry chef at the Dorchester now, but started out as a cook in a two-star hotel.
• His two passions were animals and flying: he never made it as a vet but became a successful pilot.

If you would like more practice more please visit our in the You, Me and Us part of our website.