Íssemos

Íssemos is a nonstandard or historically observed form that appears in some Portuguese texts. It is not listed as a standard conjugation in modern Portuguese dictionaries, and major grammars do not treat it as a separate, valid verb form in contemporary usage. In standard Portuguese, the imperfect subjunctive first-person plural of verbs like ser, ir, and regular verbs ends with -ssemos, but the spelling is not given as íssemos in normative references.

Possible origins of íssemos include typographical mistakes, misreading of diacritical marks, or remnants of older orthographic practices from medieval or early modern Portuguese, when spelling varied more widely. In addition, some dialect writings or texts aiming to simulate regional speech may occasionally reproduce nonstandard spellings to convey texture or pronunciation. However, such usages are rare and not considered part of the normative grammar.

Usage guidance: for formal writing and language teaching, avoid using íssemos. If you encounter it in a text, it is best treated as nonstandard, erroneous, or a contextual artifact and corrected to the standard form appropriate to the verb and context.

Examples of standard forms in hypothetical clauses include sequences like se nós fôssemos or se nós fossemos, depending on the verb stem and regional preference. These standard forms are the ones used in modern writing and instruction. See also Portuguese grammar and subjunctive mood conventions for further guidance.