Japanese speakers
Mistake: Pronouncing it as "TOORUDO YU" with a hard final d, dark l fully articulated, and full [ju:].
Why: Katakana English preserves each letter; the d+y coalescence is unfamiliar.
Fix: The d of "told" and the y of "you" merge into [dʒ], and "you" reduces to schwa: [ˈtoʊldʒə]. Written informally as "toldja" — hear it in the classic "I told ya so!".
Korean speakers
Mistake: Producing a clear released [d] and full [ju:] vowel with syllable break.
Why: Korean orthography maps directly to sound; contractions are typically absent.
Fix: The d + y coalescence produces [dʒ] (the j in "judge"): [ˈtoʊldʒə]. Same rule as "did you → didja" and "would you → wouldja".
Spanish speakers
Mistake: Producing the y as Spanish [j] with friction, blocking the coalescence.
Why: Spanish [j] retains its identity next to preceding stops.
Fix: Let d + y merge to [dʒ]: [ˈtoʊldʒə]. And use dark l [ɫ] for the l in "told", not the light Spanish l.