Sumerjo is the 'I' form of the verb sumergir, which means 'to submerge' or 'to plunge'. It's a powerful verb that creates a vivid image of being underwater.
In this emotional ballad, Laura Pausini sings "Y las sumerjo en un lamento" (And I submerge them in a lament). She uses this word metaphorically to describe drowning her unspoken words in sadness, words she can no longer say to the person she misses.
Italian pop singer Laura Pausini hits you right in the chest with "En Cambio No" (On the Contrary, No). The whole track revolves around the sudden, crushing silence when someone is gone before you could say what mattered. She opens with "Quizás bastaba respirar / Sólo respirar muy lento" (Maybe it was enough just to breathe / Only breathe very slowly), wishing she could pause time and steady her racing heart. Instead, December rolls around—"Diciembre ya llegó" (December has arrived)—and leaves her stuck with thousands of unsaid words that literally shatter before leaving her mouth: "se rompen en mis dientes / las cosas importantes" (the important things break against my teeth).
The phrase "En cambio no" is the emotional core here. In Spanish, en cambio usually means "on the other hand" or "instead." Pausini uses it like a firm wall: you want more time, but instead, no, today there is no chance to explain, nor to ask "si te amé lo suficiente" (if I loved you enough). Between memories of running in the wind ("Corríamos al viento") and the heavy ache of remaining behind, she delivers a direct look at regret that refuses to sugarcoat how late "too late" really is.