In casual American English, "How did you learn to cook so well?" sounds like "HOW dihd yuh LURN tuh KUUK SOH wehl". Several things happen here, and the headline one is the Unreleased Stops: the final stop consonant closes without a puff of air. Keep stressed words long, unstressed words short, and link the consonants forward into the vowels.
Now you try.
Read the sentence out loud at native speed. The mic stays on your device — nothing's uploaded.
What makes this sentence sound American.
In "cook", the "" is not released — the articulators get into position but hold without the burst of air. This is called the Unreleased Stops, and it's why Americans sound more relaxed than the textbook. It comes out as KUUK.
What's happening in this sentence.
Small tricks that turn a textbook sentence into how an American actually says it.
Common pronunciation mistakes in American English.
The textbook way isn't wrong — it's just not how anyone actually says it.
Treating every L the same.
The L in "well" is a dark L — the back of the tongue rises toward the soft palate, adding a small "uh" quality before the L. Dark L adds a small schwa-like "uh" before the L. The back of the tongue lifts toward the soft palate.
Releasing the final consonant with a puff of air.
In "cook", the "" is not released — the articulators get into position but hold without the burst of air. Air stops but there's no release burst — the articulators hold position.
Saying the consonants separately.
The "" at the end of "" and the "y" starting "" blend together into "" — natural in casual conversation; in formal or careful speech, the two sounds stay separate. The two sounds merge: T+Y → CH, D+Y → J, S+Y → SH, Z+Y → ZH.
Pronouncing the function word too fully.
"you" is a function word — in connected speech, the full vowel reduces to a quick "" sound and consonants may simplify. Full vowel reduces to schwa /ə/ or other weak vowel. Consonants may simplify.