“The word meter derives from the Greek metron, meaning ‘measure, rule.’ In literary criticism, the term is most commonly used to refer to systems employed to measure the rhythm of poetry. Of the three principal systems of measurement, the most widely used is the accentual-syllabic, which attempts to mark the accented and unaccented sounds in a line of poetry, as well as the number of syllables.
The simplest way to approach the accentual-syllabic system of measurement is to begin by dividing a line of poetry into syllables and noting the relative stress given to each syllable. Generally speaking, monosyllabic nouns (boy, girl, tree); monosyllabic verbs (walk, see, breathe); and monosyllabic adjectives (red, tall, old) receive emphasis or accent when a line is read in a natural voice. That is to say, these are generally stressed syllables. Articles (a, the); monosyllabic prepositions (of, in, at); possessive pronouns (my, his, their); and suffixes (-est, -ing, -ed) do not receive emphasis or accent. That is to say, they are generally unstressed. Monosyllabic conjunctions (and, or); monosyllabic auxilliary verbs (can, have, may); and ‘to be’ verbs (is, are, was, were) are generally unstressed as well.Polysyllabic words (trouble, inspire, nightingale) require closer scrutiny to determine the relative stress or unstress of syllables; however, if the reader cannot determine the stressed syllables by ear, he or she may find the words in a dictionary and note which syllables are accented.” (emphasis in original, p.101)
Ref: Edwin Barton and Glenda Hudson (c1997) A Contemporary Guide to Literary Terms with Strategies for Writing Essays about literature. Houghton Mifflin Company: Boston and New York)