Which of the following words is an example of a -ck ending?

The word 'duck' is an example of a -ck ending because it concludes with the letters 'c' followed by 'k', which together represent the specific sound that the -ck ending produces. In the case of 'duck,' the 'ck' signifies a voiceless velar plosive sound, which is typical for this ending. This ending often appears in one-syllable words where a short vowel sound precedes it; 'duck' illustrates this pattern well.

In the other options, 'king' ends with 'ng', 'witch' ends with 'ch', and 'write' ends with 'te'. These different endings do not fit the -ck pattern, demonstrating how important the exact combination of letters is in phonics and spelling, particularly in structured language education where accurate identification of sound patterns can aid in reading and writing skills development.