Learn Portuguese (Portugal): Este é o funcionário que trabalha no departamento. - This is the employee who works in the department.

In Portuguese, the relative pronoun que is very flexible and is used for both people and things. It can translate to 'who', 'which', or 'that'. You might know that quem means 'who', but as a relative pronoun, quem is mostly used after prepositions (like com quem). When referring directly back to a noun like o funcionário, que is the natural choice.

If we were talking about multiple female employees, would que change to a plural or feminine form?

No, the relative pronoun que is invariable. It never changes its form, regardless of the gender or number of the noun it refers to. If the subject changed, it would still be as funcionárias que trabalham no departamento.

Why does the sentence use no instead of em o for 'in the'?

The preposition em (in/on/at) always combines with the definite article o (the, masculine singular) to form the mandatory contraction no. In Portuguese, you must use these joined forms rather than leaving the words separate.

Could I say Esse é o funcionário instead of Este é o funcionário?