Japanese speakers
Mistake: Pronouncing it as "RUKKUDO BAKKU" with a full -ed suffix vowel and hard consonants.
Why: Katakana English preserves each letter; the -ed suffix behavior in English is complex.
Fix: The -ed after voiceless [k] becomes voiceless [t], not [d] or [əd]: "looked" = [lʊkt]. Then the [t] elides before [b]: [ˈlʊkˈbæk]. Say "lookback" as one prosodic unit.
Korean speakers
Mistake: Producing [-ed] as [ɪd] extra syllable, or hard released [t].
Why: Korean orthography and English -ed rules differ.
Fix: The -ed after voiceless consonants (k/p/f/s/tʃ/ʃ) is pronounced [t] with no extra syllable. "Looked" is 1 syllable [lʊkt]. Then t elides before b: [ˈlʊkˈbæk].
Spanish speakers
Mistake: Producing [-ed] as [eð] or [ed] extra syllable.
Why: Spanish preserves letters; English -ed has 3 realizations depending on preceding sound.
Fix: -ed after [k] = [t]: "looked" = [lʊkt] (1 syllable). Then t elides before b: [ˈlʊkˈbæk]. English -ed rule: voiceless C + [t], voiced C + [d], t/d + [ɪd].