Initial-stress derivation is a phonological process in English that moves stress to the first syllable of verbs when they are used as nouns or adjectives. (This is an example of a suprafix.) This process can be found in the case of several dozen verb-noun and verb-adjective pairs and is gradually becoming more standardized in some English dialects, but it is not present in all. The list of affected words differs from area to area, and often depends on whether a word is used metaphorically or not. At least 170 verb-noun or verb-adjective pairs exist. Some examples are:
In English, since the early modern period,[failed verification] polysyllabic nouns tend to have an unstressed final syllable, while verbs do not. Thus, the stress difference between nouns and verbs applies generally in English, not just to otherwise-identical noun-verb pairs. The frequency of such pairs in English is a result of the productivity of class conversion.
When "re-" is prefixed to a monosyllabic word, and the word gains currency both as a noun and as a verb, it usually fits into this pattern, although, as the following list makes clear, most words fitting this pattern do not match that description.
Many of these have first syllables that evolved from Latin prepositions, although again that does not account for all of them. See also list of Latin words with English derivatives.
When the stress is moved, the pronunciation, especially of vowels, often changes in other ways as well. Most common is the reduction of a vowel sound to a schwa when it becomes unstressed.
absent · abstract · accent · addict · address (North America only) · affect · affix · alloy · ally · annex · assay · attribute · augment · belay · bisect · bombard · combat · combine · commune · compact · complex · composite · compost · compound · compress · concert · conduct · confect · confine(s) · conflict · conscript · conserve · consist · console · consort · construct · consult · content · contest · contract · contrast · converse · convert · convict · decrease · default · defect · desert · detail · dictate · digest · discard · discharge · disconnect · discount · discourse · dismount · display · embed · envelope · escort · essay · excise · exploit · export · extract · ferment · finance · foretaste · forward · frequent · gallant · impact · implant · impound · import · impress · imprint · incense · incline · increase · indent · inlay · insert · insult · intercept · interchange · intercross · interdict · interlink · interlock · intern · interplay · interspace · interweave · intrigue · invert · invite · involute · laminate · mandate · mismatch · misprint · object · offset · overcount · overlap · overlay · overlook · override · overrun · perfect · perfume · permit · pervert · prefix · present · proceed(s) · process · produce · progress · project · protest · purport · rebel · recall · recap · recess · recoil · record · recount · redirect · redo · redress · refill · refresh · refund · refuse · regress · rehash · reject · relapse · relay · remake · repeat · repose · repost · reprint · research · reserve · reset · retake · retard · retract · retread · rewrite · segment · separate · subject · survey · suspect · torment · transfer · transform · transplant · transect · transport · transpose · traverse · undercount · upgrade · uplift · upset
Some two-word phrases follow this pattern. Nouns derived from phrasal verbs like the following are written solid or hyphenated: hand out, drop out, hand over, crack down, follow through, come back.
If the derived noun is widely used (for example "the backup"), its spelling may cause widespread modified spelling of the verb (*to backup instead of to back up). However, the past tense of such verbs is very rarely written as *backedup or *backupped, but almost always as backed up.
In some cases the spelling changes when the accent moves to another syllable, as in the following verb/noun pairs which show the addition of a "magic e", which changes the previous vowel from lax to tense:
In British English, annexe is the noun from the verb annex. The verb secrete "conceal" probably derives from the noun secret rather than vice versa.
Pronunciations vary geographically. Some words here may belong on this list according to pronunciations prevailing in some regions, but not according to those in others. Some speakers, for example, would consider display as one of these words. For some other speakers, however, address carries stress on the final syllable in both the noun and the verb. There is a dialect in the United States referred to informally by linguists as P/U or police/umbrella because many nouns are stressed on the first syllable; including police, umbrella, and many verb-derived nouns. Some dialects of Scottish English have this in "police".
Some derived nouns are used only in restricted senses; often there is a more generic noun not identical in spelling to the verb. For instance, to combine is to put together, whereas a combine may be a farm machine or a railway car; the generic noun is combination. Perhaps transpose is used as a noun only by mathematicians; the transpose of a matrix is the result of the process of transposition of the matrix; the two-syllable noun and the four-syllable noun differ in meaning in that one is the result and the other is the process. Similar remarks apply to transform; the process is transformation, the result of the process is the transform, as in Laplace transform, Fourier transform, etc.
In the case of the word protest, as a noun it has the stress on the first syllable, but as a verb its meaning depends on stress: with the stress on the second syllable it means to raise a protest; on the first it means to participate in a protest. This appears to result from the derived noun being verbed.
Entrance is also a noun when stressed on the first syllable and a verb when on the second, but that is not a true example since the words are unrelated homographs.
noun-verb stress alternation occurred only in the beginning of the modern period