Intrusion is a form of catenation, also sometimes called liaison : See Catenation / Liaison
- Definition : The insertion of a consonant between two vowel sounds to aid pronunciation - in English the approximants (semi-vowels) /j/ /w/ and /r/ are used.
- Examples : Two of (them) /tu:wəv/ Three of (them) /θri:jəv/ Four of (them) /fɔ:rəv/ he is /hijɪz/ to Italy /tu:wɪtəli:/ saw it /sɔ:rɪt/
- In rhotic accents (eg some American accents) the post vocalic /r/ will anyway be pronounced and is therefore no longer "intrusive".
- These consonants are called "semi-vowels" because they are close to vowels in quality (there is almost no obstruction of the air as it passes from the lungs). They are therefore the "easiest" consonants to pronounce between two vowels.
- Problems for students : A common mistake of Italian learners is to try to use /h/ in this way, producing eg /hi hɪz/