In the literature, the universal definite quantifier ambos ‘both’, unlike its equivalent os dois ‘the two’, is regarded as almost exclusively distributive, inasmuch as it blocks collective readings, except in a few special contexts. These include instrumental adjuncts (as in the counterpart of ‘he lifted the box with both hands’) and, only for some speakers, operators of the type of mesmo ‘same’ (as in the counterpart of ‘they both attend the same school’). Sentences with ambos and collectivizing predicates, such as symmetric adjectives (diferente ‘different’), reciprocal operators (um com o outro ‘each other’), collectivizing adverbials (em conjunto ‘together’), quasi-divisible predicates (unir esforços ‘join efforts’) or indivisible predicates (somar 12 ‘equal 12’) are generally considered anomalous. In this paper, the use of ambos in contemporary standard (mainly European) Portuguese is assessed, taking into account all these critical contexts. The observation of data from contemporary newspaper writing and from literary text (of the past 500 years) and the data from a survey among 20 native speakers (linguistic experts) shows that this is an area of exceptionally intense linguistic variation, where signs of significant linguistic change are additionally observed.