You read Lucía está en su cuarto and a quiet voice says Lucía is in her room, half a second behind. Every sentence gets its English echo.
At some point someone told you to stop doing that. Think in Spanish. Translating is a crutch. So you tried. You banned the English voice, read the next line, and it came apart in your hands: words you know, in an order you know, and no idea what the sentence meant.
That's worth paying attention to, because it tells you what the English was doing.
What the translating is for
In 1994 a researcher named Richard Kern sat 51 intermediate learners of French down with French texts and asked them to think out loud while they read. He wanted to know when they translated, and why. (His paper is here, if you want the original.)
His argument is kinder than the forum advice. Translating lets you hold on to a stretch of text that's more than you can manage in the new language, by storing it in a form your memory already handles easily. The meaning stays in one piece while you work out the next bit.
And the part learners rarely hear: the stronger readers translated less than the weaker ones. The voice was doing the most work for the readers who needed it most.
Why forcing it off backfires
Your working memory is a small bag. A Spanish sentence at the edge of your level fills it up fast, and English is the compact version, the thing that fits.
Take the English away by force and the bag overflows. You get fragments. Then you get the feeling that you're bad at this, which makes the next sentence harder to hold, and so on down. (I wrote once about blaming the wrong thing when words won't stick, and this is a cousin of that.)
The voice tends to fade once the Spanish stops overflowing the bag. That happens when the sentences get easier for you, either because you've grown or because you picked easier ones.
What actually thins it out
Easy reading, and reading things twice.
On a first read, meaning and language arrive together and compete for the same small bag. On a second read the meaning is already there. What's left over goes to the Spanish, and that's usually the first place you catch a whole paragraph going by without its English echo.
There's a story in my Mindfulness book for beginners where a mother takes her nervous daughter into the garden to watch the clouds. No necesitas pelear con tus pensamientos. Solo observa. You don't need to fight your thoughts. Just watch them.
It works for the English voice too. Let it come, and notice the moments when it doesn't.
A small experiment for this week
Pick a story a notch below your level. If you read intermediate Spanish, take a beginner story. If you're a beginner, take one you've already finished. The free book is a good place to find one, and so is the Mindfulness Beginner collection, where the stories are short enough to read twice in one sitting.
Read it once however you like. English voice, dictionary, the translation if your book has one, all of it.
Tomorrow, read the same story again. After each paragraph, stop and ask one question: did English show up just now? If it didn't, put a small tick in the margin.
Count only the ticks.
Next week, a new story at the same easy level, read twice the same way. The ticks will turn up sooner in the second read, and then some of them in the first. That's the voice coming down on its own schedule, which is the only way it ever does.
¡Ánimo!
Ariel