Explain the differences in pronunciation with reference to the sounds[p, t, k] in the following examples: - stop and spot [p], tin and tone [t], skirt and kick [k]

The [p] is different because in in the first word it does not have an audible release since it's located in the end. T has a little puff of air in tin which is called aspiration and is marked with a small h in phonemic transcription. Final k in kick also has no audible release while skirt has one.