The sound [ θ ] in the word "thank" is found in I (initial syllable). It is the unvoiced partner of the" voiced th" /ð/ (you make sound with the vocal cords) that we can find for example in the words "the, father".
In both cases the tip of the tongue is placed behind the top front teeth. Other examples of [ θ ] sound can be seen in "three", "think", "thin".
In the word thank the sound [ θ ] is found in I that is the initial syllable. It is the unvoiced partner of the voiced partner. The voiced partner here is "th".
A syllable is defined as a unit of pronunciation having one vowel sound, with or without consonants, forming the whole or a part of a word.
The reason for the initial syllable is in that case the tongue is placed behind the top front teeth. Other such examples of the sound [ θ ] are thick, thin, three, through, though, and many more.
To know more about the initial syllable of the sound [ θ ], refer to the link below:
https://brainly.com/question/24697570?referrer=searchResults
