English is a stress-timed language, which means that words of more than one syllable have one syllable which is more pronounced than the other(s) e.g. travel, or account.
In most two-syllable words this stress pattern does not change, even if the word is used as a different part of speech (verb-noun). Thus in the well-known phrase ‘travel broadens the mind’, ‘travel’ is an uncountable noun. Compare with ‘I have to travel a lot for my job’, where ‘travel’ is a verb. In both sentences ‘travel’ is stressed on the first syllable ie; travel. Similarly, in the phrase ‘My account is overdrawn’, ‘account’ is a countable noun, while it is a verb in the sentence ‘She had to account for the loss of several major clients’. In both, ‘account’ is stressed account.
However, there is a group of common two-syllable words in which the stress of the word changes, or moves, depending on whether it is a noun or a verb. In general, the noun is stressed on the first syllable, the verb on the second, e.g; import. In the sentence ‘Croatia imports natural gas from Russia’, ‘import’ is a verb, stressed import, whereas in the phrase ‘Imports of natural gas have been disrupted’, ‘imports’ is a countable noun, stressed imports. Another example is ‘increase’: compare ‘There has been an increase in unemployment recently’ with ‘The cost of living seems to increase month on month’. In the first example ‘increase’ is a countable noun, stressed increase, while in the second it is a verb, stressed increase.
