Common mistakes by native language
Japanese speakers
Mistake: Producing a fully released, aspirated t in "it" and "up" — "look-ee-to-up" — which adds syllables that don't exist in the target pronunciation.
Why: English loanwords in Japanese (e.g., ルック, アップ) always end in a full vowel-supported consonant, and this pattern carries over into English, blocking the flap that General American speakers use between vowels.
Fix: Both t's in "look it up" sit between vowel sounds and become a fast flapped [ɾ], just like the tt in "butter". The phrase becomes [ˈlʊkɪˈɾʌp] — practice saying "loo-ki-dup" quickly to internalize the tap.
Korean speakers
Mistake: Treating each word as its own rhythmic unit with a mini-stop before "up", producing "look it. up." instead of one continuous phrase.
Why: Korean tends toward syllable-timed rhythm with clear boundaries at each syllable block, which conflicts with English's tendency to fuse function words and short verbs into a single stress-timed unit.
Fix: Say the whole phrase in one breath with a single main stress on "look": [ˈlʊkɪˈɾʌp]. The k of "look" links into "it", and the t of "it" flaps directly into "up" — no gaps anywhere.
Chinese speakers
Mistake: Giving "it" a stressed, clear vowel [ɪt] with a released final t, disrupting the weak, fast pronoun reduction expected in the middle of the phrase.
Why: Mandarin doesn't have unstressed function words that reduce the way English pronouns do mid-phrase, so "it" tends to get equal prominence to "look" and "up" rather than collapsing into an unstressed syllable.
Fix: Keep "look" and "up" as the two stressed beats, and let "it" become a quick, unstressed connector between them: [ˈlʊkɪˈɾʌp]. The middle syllable should feel almost swallowed compared to the strong beats on either side.
Notes
"Look it up" is a classic three-word phrasal verb that English learners meet as early as A1, usually in classroom instructions about dictionaries. Phonetically, it's a compact showcase of General American connected speech: the k of "look" links smoothly onto the vowel of "it", and the t of "it" — sitting between two vowels — flaps into a quick tap rather than a full stop, producing [ˈlʊkɪˈɾʌp]. Learners who instead pronounce every consonant crisply end up with a robotic four- or five-beat rhythm instead of the natural three-beat flow native speakers use. Because the verb-pronoun-particle structure of "look it up" repeats constantly across other phrasal verbs ("pick it up", "turn it off", "fill it in"), internalizing its rhythm early gives learners a transferable pattern that pays off across dozens of everyday expressions.