<P> In the description of some languages, the term chroneme has been used to indicate contrastive length or duration of phonemes . In languages in which tones are phonemic, the tone phonemes may be called tonemes . Though not all scholars working on such languages use these terms, they are by no means obsolete . </P> <P> By analogy with the phoneme, linguists have proposed other sorts of underlying objects, giving them names with the suffix - eme, such as morpheme and grapheme . These are sometimes called emic units . The latter term was first used by Kenneth Pike, who also generalized the concepts of emic and etic description (from phonemic and phonetic respectively) to applications outside linguistics . </P> <P> Languages do not generally allow words or syllables to be built of any arbitrary sequences of phonemes; there are phonotactic restrictions on which sequences of phonemes are possible and in which environments certain phonemes can occur . Phonemes that are significantly limited by such restrictions may be called restricted phonemes . </P> <P> In English, examples of such restrictions include: </P>

With three good examples each list the phonemes of english