Breakdown of Não se trata de um segredo comercial.
não
not / no
um
a / an / some (all forms)
o segredo
the secret
tratar-se de
to be a matter of / to concern
Questions & Answers about Não se trata de um segredo comercial.
How exactly does tratar-se de work here, and who is doing the action?
The verb tratar normally means to treat or to handle, but the reflexive form tratar-se de is an impersonal expression. This means it doesn't have a specific subject doing the action. It translates to 'it is about' or 'it is a matter of'. Because it is impersonal, it is always conjugated in the third-person singular.
Why is the pronoun se before the verb instead of after it?
In European Portuguese, object pronouns typically attach to the end of the verb. However, negative words like não act as magnets that pull the pronoun in front of the verb (a rule known as proclisis). If you made this sentence positive, the pronoun would flip back to the end: Trata-se de um segredo comercial.
If there were multiple secrets, would the verb become plural (tratam-se)?
Could I just use the verb ser and say Não é sobre um segredo comercial?