I’ve always thought of the verb Assistir as a straightforward false friend, meaning, as it does, to attend or spectate at an event, and has nothing to do with helping or supporting any way. But today I was reading the book “Trilby” by George Du Maurier, written at the back end of the nineteenth century and I came across this sentence
And, indeed, here was this immense audience, made up of the most cynically critical people in the world, and the most anti-German, assisting with rapt ears and streaming eyes at the imagined spectacle of a simple German damsel, a Mädchen, a Fräulein, just “verlobte”—a future Hausfrau—sitting under a walnut-tree in some suburban garden
That really sounds like a very Portuguese use of the word “assist”. So I looked in my trusty Chambers and it turns out that assist had, in Shakespeare’s day, much the same meaning as its cognate does in Portuguese. What’s more, when I checked the priberam online dictionary I found that Assistir has several senses, including the British one. They give as it’s synonyms Ajudar, Socorrer and Cooperar.
So what we have is a word with two distinct meanings, in the process of diverging, where one sense is dominant in English and the other in Portuguese, but while the lesser sense is still used in Portuguese, the lesser sense in English has all but faded away to nothing.