Rã vs. perereca vs. sapo
In Portuguese, while all referring to amphibians, the words rã, perereca, and the related sapo are not interchangeable. They distinguish between different types of anurans based on their physical characteristics and habitats, similar to the distinction between frog and toad in English, but with an extra common category.
Rã
A2This word is the closest equivalent to the general English word frog. It specifically refers to amphibians with smooth, moist skin, long and powerful hind legs adapted for jumping, and a life closely tied to water. They are typically found in or near lakes, ponds, and rivers.
O coaxar da rã ecoava pelo pântano durante a noite.
(The croaking of the frog echoed through the swamp during the night.)
A rã deu um salto impressionante da margem para dentro do lago.
(The frog made an impressive leap from the bank into the lake.)
Em alguns restaurantes, coxas de rã são consideradas uma iguaria.
(In some restaurants, frog legs are considered a delicacy.)
Perereca
B1This word translates to tree frog. A perereca is typically smaller than a rã, has very smooth skin, and is distinguished by the adhesive discs on its fingertips, which allow it to climb surfaces like trees, plants, and even glass windows. They are excellent climbers.
Havia uma pequena perereca verde grudada na janela da cozinha.
(There was a small green tree frog stuck to the kitchen window.)
As crianças encontraram uma perereca descansando em uma folha larga no jardim.
(The children found a tree frog resting on a large leaf in the garden.)
O som da perereca é mais agudo e se parece com um assobio.
(The sound of the tree frog is higher-pitched and sounds like a whistle.)
Sapo
A1This word is the direct equivalent of toad. A sapo is characterized by its warty, dry-looking skin, a stout body, and shorter hind legs, making it more of a hopper than a jumper. They are more terrestrial and often found in gardens and forests, away from large bodies of water.
Um grande sapo apareceu no quintal depois da chuva forte.
(A large toad appeared in the yard after the heavy rain.)
A pele do sapo é mais rugosa e seca que a da rã.
(The toad's skin is rougher and drier than the frog's.)
É um mito popular que tocar em um sapo pode causar verrugas.
(It is a popular myth that touching a toad can cause warts.)
Summary
In short: a rã is the classic, water-loving frog with long jumping legs and smooth skin. A perereca is a small, climbing tree frog with adhesive pads on its toes. A sapo is a terrestrial toad with stout, warty skin and shorter legs for hopping. While these are the technical distinctions, be aware that in colloquial speech, people may sometimes use the terms a bit more loosely.