When reporting someone's orders, requests, or wishes from the past, Portuguese requires a specific tense shift in the dependent clause.
Backshifting the Subjunctive
When you express a wish, command, or request in the present (e.g., "I demand that we accept..."), the dependent verb takes the Present Subjunctive (Presente do Conjuntivo).
However, when you report this same event in the past (e.g., "He demanded that we accept..."), the main verb moves to the past tense. To keep the timeline consistent, the dependent verb must "backshift" into the Imperfect Subjunctive (Pretérito Imperfeito do Conjuntivo). You will easily recognize this tense by its characteristic -ss- endings (such as -sse, -ssem, or -ssemos).
Observe how past-tense orders and demands trigger the Imperfect Subjunctive in the reported clause:
Wishes, Requests, and Pleas
This backshifting rule applies to any past-tense verb that triggers the subjunctive due to will, influence, or emotion. Whether the historical figure was making a wish (querer), a request (pedir), a suggestion (sugerir), or a desperate plea (suplicar), the following clause must use the Imperfect Subjunctive.