When you sign contracts (for instance a promissory agreement of purchase and sale) in both versions, e.g. in Portuguese and in English, you can introduce a clause specifying which version shall prevail in case of any question arising from the interpretation of the contract. The version that prevails can either be Portuguese or English.
The Public Deed of Purchase and Sale (commonly referred to as “Escritura Pública de Compra e Venda”), which is usually prepared and verified by a Notary (who will certify that the purchase and sale agreement of the property was drawn up correctly, that the purchase price is paid to the vendor, that the necessary documents regarding the property are duly gathered, the identity of the parties and file for the registration of the sale) the contract will necessarily be done in Portuguese. However, In case one of the grantors is a foreigner and does not understand Portuguese the notary will translate the document and explain it using a language that is understood by the foreigner.
(Villa for sale in Lagoa, Algarve, Portugal, pictured.)