1, the use is limited by the environment.

Free variation is a kind of phoneme variation, which means that there is no environmental restriction and conditional variation belongs to a phoneme. Its appearance is limited by certain conditions, and it can only appear if it has certain phonetic conditions. Without the corresponding conditions, this variation generally does not occur.

2. Use different methods

Free variants are phoneme variants that can be freely replaced without affecting the meaning, also known as "habitual variants", which can be divided into two types: partial free variants and complete free variants. Although conditional variants belong to the same phoneme, they cannot be used interchangeably due to the limitation of phonetic conditions.

3. The meaning is different after use.

Although the phonemes of free variants have different sound qualities, people who speak this language or dialect do not think that they are different sounds, and their meanings have not changed after use, but they are used as the same phonetic unit. The conditional variable is not.

Example of free variables:

For example, [n] and [l] in Wuhan dialect of Chinese can be changed freely without changing their meanings. In this kind of words, "Nan" and "Lan" are homonyms and can be pronounced as [Lan] or [Nan]. [n] and [l] are two free variants of /n/ phoneme in Wuhan dialect.

Examples of conditional variables:

There are five typical conditional variants of /A/ phoneme in Mandarin Chinese, which have their own complementary distribution environments:

Examples of environments in which phoneme variants appear

[? ] The center lower lip is not round, or is it alone with the consonant [? ], ma [m? ]

[a] the vowel of disyllabic ai, the nasal vowel of ia an Mai, Jia T? Ia], fuck [Kay]

[α] vowels of low-lip non-circular lip disyllabic, ao, nasal vowels ang Lao [lαu] and Fang [f' α η]

[? ] the first half of the low non-circular lip nasal vowel ian, Luan Tian [t 'i? N], spring [t?' y？ n]

[? ] the front handle of the central low neutral consonant [p]

Baidu encyclopedia-free variant

Baidu encyclopedia-conditional variant