From Hull AWE
Two (related) words are written combine. They are pronounced differently, having different stresses.
- The first is the well-established verb 'to combine', meaning 'to join' transitive, 'mix' (in cookery and chemistry, etc.) or 'co-operate for mutual advantage' (in politics and history, etc.). In this sense, the stress falls on the second syllable: 'kerm-BINE', IPA: /kəm ˈbaɪn/.
- As a noun or adjective, combine usually has the stress on the first syllable: 'IPA: /ˈkɒm baɪn/ COM-bine', though traditionally in Britain it had the same pronunciation as the verb above. The compound noun 'a combine harvester' (an agricultural machine that cuts corn, threshes it, bags the grain and binds the straw in a single (combined) operation) where the stress is on the first syllable, has given rise to the farmers' verb 'to combine', e.g. a field, or a crop (i.e. to harvest it with a combine harvester), where the stress is also on the first syllable, unlike the usual pronunciation of the verb.
- This pattern of shifting stress in words that look identical but belong to two separate word classes is quite common in English. Quirk (1985) (Appendix I.56 B) remarks: "When verbs of two syllables are converted into nouns, the stress is sometimes shifted from the second to the first syllable. The first syllable, typically a Latin prefix, often has a reduced vowel /ə/ in the verb but a full vowel in the noun:
- There follows a list of some 57 "words having end-stress as verbs but initial stress as nouns in Br[itish] E[nglish]." Note that "in Am[erican] E[nglish], many have initial stress as verbs also". Quirk's list is the foundation of AWE's category:shift of stress. Additions have been made from, amongst others, Fowler, 1926-1996.