Spanish · Pronunciation Guide
el LOO-nehs — the u is a rounded "oo", and the article is what turns it into on Monday.
Two syllables in the noun, LU-nes, beat on the first. Ending in s puts it under the default rule with no accent needed. The curiosity here is that "lunes" already ends in s in the singular, so its plural is identical — "los lunes" versus "el lunes", with only the article distinguishing one Monday from every Monday.
Listen: el lunes
Free browser voice. Hear it read by a real native speaker inside the LingoDrop app.
El lunes empiezan las clases.
Classes start on Monday.
Listen: El lunes empiezan las clases.
Free browser voice. Hear it read by a real native speaker inside the LingoDrop app.
"El lunes empiezan las clases" uses the article where English uses the preposition on — Spanish never says "en lunes". "Empiezan" shows the stem change from "empezar", with ie in one beat and the z becoming a plain s sound. Note days of the week are not capitalised in Spanish.
English offers two wrong vowels here — the "loo" of "lunar" with its y glide, or worse, the flat vowel of "lunch". Spanish wants a clean rounded "oo". The two l's then get run together carelessly — say them as separate bright l's. And learners add a preposition, producing "en el lunes", when the article alone carries the meaning.