Descrição de duas oliveiras, uma grande e outra pequena

Why does Portuguese say “pequenina” instead of “pequena”?

Portuguese sprinkles the diminutive -inha more freely than Spanish or Italian, and it can stack onto adjectives as well as nouns. Pequena (“small”) becomes pequenina (“very small, tiny”). Erva (“grass, herb”) becomes ervinha (“little weed”). The doubled diminutive marks both physical smallness and a softer, almost protective tone. European Portuguese uses pequenina casually; Brazilian Portuguese leans even harder into stacked diminutives.

In this clip, a narrator describes two olive trees: “Uma é pequenina, muito pequenina, e a outra é grande... está aqui no meio das ervinhas” (“One is tiny, really tiny, and the other is big... it’s here among the little weeds”).