Distinguir vs. discernir
While both distinguir and discernir can be translated as to make out or to discern in the sense of managing to see something, they carry subtle differences. Distinguir leans towards identifying or separating something from its context, while discernir implies a deeper level of perception or mental effort to understand what is being seen.
Distinguir
B1This word focuses on the act of separating or identifying something from its surroundings or from other similar things. It is akin to telling apart or making out a specific shape or object against a background.
Ao longe, mal conseguia distinguir a silhueta do castelo.
(In the distance, I could barely make out the silhouette of the castle.)
Estava tão escuro que não distinguia as feições do seu rosto.
(It was so dark that I could not distinguish the features of his face.)
É preciso ter um bom olho para distinguir estas duas espécies de pássaros.
(You need a good eye to distinguish between these two species of birds.)
Da janela do avião, já era possível distinguir as casas e as estradas.
(From the plane window, it was already possible to make out the houses and the roads.)
Discernir
B2This word emphasizes the act of perceiving something that is unclear, faint, or complex. It often implies that a level of mental effort, judgment, or insight is needed to truly understand or recognize what is being seen or perceived.
Com o telescópio, o astrónomo conseguiu discernir os anéis de Saturno.
(With the telescope, the astronomer was able to discern the rings of Saturn.)
Na neblina densa, era quase impossível discernir o caminho à nossa frente.
(In the dense fog, it was almost impossible to discern the path ahead of us.)
Ele tentava discernir um movimento suspeito na escuridão do armazém.
(He was trying to discern a suspicious movement in the darkness of the warehouse.)
Através do ruído da festa, consegui discernir a melodia da minha canção favorita.
(Through the noise of the party, I managed to discern the melody of my favorite song.)
Summary
In essence, use distinguir when the main action is to identify or tell one thing apart from another (e.g., a ship on the horizon, one twin from another). Use discernir when the action involves a more challenging perception of something unclear or subtle, requiring focus or insight (e.g., details on an old map, a figure in a blizzard). While they can be interchangeable in simple situations like seeing in the fog, distinguir is about identification, and discernir is about perceptive understanding.