Common mistakes by native language
Japanese speakers
Mistake: Devoicing the final consonant of "his" to [s] and adding a pause before "eyes": "HISU, AIZU".
Why: Japanese has no voiced-z equivalent at the end of a word in this context, and katakana loanwords devoice and separate final consonants with an extra vowel.
Fix: Keep "his" fully voiced as [hɪz] and link the z directly onto "eyes": [hɪˈzaɪz], one smooth flowing phrase.
Korean speakers
Mistake: Pronouncing "his" with a clipped, unvoiced final sound before a short break, then starting "eyes" separately.
Why: Korean lacks a voiced /z/ sound entirely, so learners often substitute a voiceless [s] and treat the word as phonetically "closed".
Fix: Voice the final consonant of "his" fully and let it glide into the vowel of "eyes": [hɪˈzaɪz], keeping the buzz of [z] going right up to the diphthong.
Chinese speakers
Mistake: Producing "his" and "eyes" as two distinct syllables with a small gap, and losing the voicing on the final z.
Why: Mandarin does not distinguish voiced and voiceless sibilants in this position, so the z/s contrast and the linking that depends on it are both easy to miss.
Fix: Link the voiced z of "his" straight into "eyes" with no gap: [hɪˈzaɪz], keeping continuous voicing across the whole phrase.
Notes
"His eyes" links a voiced sibilant to a following diphthong, and getting the linking right depends first on getting the voicing right: "his" ends in [z], not [s], even though the spelling might suggest otherwise. Once the z is correctly voiced, it links effortlessly onto the vowel that opens "eyes", producing [hɪˈzaɪz] as one continuous phrase rather than two separate words. This is the same general linking rule seen throughout connected English speech — no pause exists between a word-final consonant and a following vowel — but it is worth practicing specifically with voiced sibilants like z, since many learners either devoice the sound or add an unnecessary break at the word boundary, both of which make the phrase sound stilted. RP and General American treat this phrase identically, with no regional variation in the linking or the vowel quality of "eyes". Because possessive pronouns like "his", "her", and "its" frequently precede vowel-initial nouns, this exact linking pattern recurs constantly across everyday descriptions of people and objects.