Intrusion is an example of linking.
Example
When we say ‘I did it!' we join together the /d/ and the /it/ to produce ‘I didit'. When we say ‘I am' we insert a /j/ sound to produce ‘I yam'.
In the classroom
Learners can be helped to distinguish how words are linked through ‘how many words did you hear?' activities, and can be encouraged to produce linked language through the teacher backchaining models for pronunciation.
Further links:
https://www.teachingenglish.org.uk/article/connected-speech
https://www.teachingenglish.org.uk/article/connected-speech-2