See video explanation here:
This video is about how pronunciation, spelling and stress shift when word endings are added to vocabulary words to change the part of speech, for examples with nouns, verbs, and adjectives. It is especially good for teachers and learners of English as a second language. The information can be used in class and for self-study. Explanations, examples, and exercises are given to help students and teachers in learning this somewhat difficult grammar and vocabulary concept. The lesson also deals with shifts in stress when making different word forms in English, for example, from verbs to nouns and adjectives.
See video on Youtube!