Timing, in linguistics, refers to the rhythmic qualities of speech in a given language, in particular how syllables are distributed across time. There are two basic ways to assign time units (or "beats") to words: stress timing and syllable timing.

In a syllable-timed language, every syllable takes up roughly the same amount of time when pronounced (so there is a constant which is the time that a syllable lasts). Spanish and Japanese are examples (more accurately, Japanese is mora-timed rather than syllable-timed—the basic concept is the same).

In a stress-timed language, syllables may last different amounts of time, but there is a given amount time (on average) between two consecutive stressed syllables, and that time is roughly a constant. English is an example of stress timing.

Of course these patterns can change over time or be borrowed from other languages. For example, Mexican Spanish, due to close contact with American English, shows a marked tendency towards stress timing. There are reports of Mexican people pronouncing "los Estados Unidos" as two syllables—which actually means the speaker marks two "beats" or stress peaks (over /ta/ and /ni/), in the same way that e. g. an Argentine speaker would mark the two syllabic peaks in a word like "pompón". The pervasive vowel reduction and shortening found in English is in part a consequence of stress timing; Mexican Spanish under this influence shows signs of vowel shortening as well.