A number of English nouns are derived from verbs. Though these nouns have the same spelling, they are stressed differently from their verbs. The nouns are stressed on the initial syllable, but the verbs are not. Here's a list of initial stress-derived nouns:
combat compound conflict contrast decrease
discount export extract import increase
insult perfect permit rebel refill
refund transplant update upgrade upset
In a few of these words, stress isn't the only difference between the noun and the verb. In combat, compound, conflict, contrast, perfect, and rebel, there's also a difference in pronunciation. For example, the first syllable of combat has a reduced vowel when the word is a verb. When combat is a noun, the first syllable has a full vowel. In compound, many speakers pronounce the first syllable with a reduced vowel when this word is a verb. This reduced vowel is also audible in the first syllables of the verbs conflict, contrast, perfect and rebel.
The words abuse, excuse and use are similar in the sense that they are both nouns and verbs. However, they are stressed the same. The difference is in the pronunciation of the final consonant. The nouns are pronounced with a word-final /s/ and the verbs with a word-final /z/.
English has many nouns which are derived from verbs and share the same spelling. However, they are stressed differently. The nouns are stressed on the initial syllable and the verbs on the final. Another category concerns nouns and verbs which share the same stress and spelling but differ in the pronunciation of the final consonant.