Everything to know about phonological assimilation in French

Updated: April 2, 2023 by Mylene in Pronunciation LessonsArray  ▪ English Français  

Consonants sounds can change depending on their environment. The changes affect the tone character of their pronunciation. Sound assimilation is a phenomenon that happens when sound is mixed with other sounds. Below, you will find out in which case a sound assimilation occurs.

• Why does assimilation happen?
• The case where the letter e is silent.
• What are the pairs of voiced and unvoiced consonants?
• The pair [t]/[d]
• The pair [s]/[z]
• The pair [f]/[v]
• The pair [ʃ]/[ʒ]
• The pair [p]/[b]
• The pair [k]/[g]

What is sound assimilation in linguistics?

Why does assimilation happen?

When a voiceless consonant is next to a voiced one, voice assimilation can occur. Assimilation is a natural thing. For example, in the word “absent”, it is easier to pronounce the sound [p] than to pronounce the sound [b]. Assimilation then happens. The unvoiced consonant [s] affects the pronunciation of the voiced consonant [b]. The voiced consonant [b] loses its voice and is pronounced [p].

• absent is pronounced [apsɑ̃].

Similarly,

• absurde is pronounced [apsyʁd].
• observe is pronounced [ɔpsɛʁve].

What is an unvoiced consonant?

Unvoiced consonants are consonants that do not require the use of vocal cords to produce a sound.

What are the non-voiced consonants?

The six non-voiced consonants are: [t], [s], [f], [ʃ], [p] and [k].

What is a voiced consonant?

A voiced consonant is a consonant that requires the use of the vocal cords to produce a sound.

What are the voiced consonants?

The 6 consonants that make a sound are: [d], [z], [v], [ʒ], [b] and [g].

You find detailed information about the spelling of the consonants of the Phonetic Alphabet.

The case where the letter e is silent

The mute e, sound [ə], can disappear when there is a single consonant pronounced in front. Deleting this silent e will allow 2 consonants to be side by side. To learn more about the pronunciation of silent e, you can read the rules when it comes to pronouncing the mute E in French.

• In the word “médecin”, the mute e is not pronounced because there is only one consonant pronounced in front, the sound [d],
• The unvoiced consonant [s] will affect the pronunciation of the voiced consonant [d],
• The consonant [d] loses its voice and is pronounced [t].
• médecin is pronounced [mɛtsɛ̃] 

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What are the unvoiced consonant / voiced consonant pairs?

There are 6 unvoiced consonant / voiced consonant pairs:

• The pair [t]/[d]
• The pair [s]/[z]
• The pair [f]/[v]
• The pair [ʃ]/[ʒ]
• The pair [p]/[b]
• The pair [k]/[g]

The pair [t]/[d]

Assimilation allows the unvoiced consonant [t] to gain its voice and be pronounced [d]. On the other hand, the voiced consonant [d] may lose its voice and become pronounced [t]. Below are two examples.

• In the word “au-dessus“, the silent e is not pronounced because there is only one consonant pronounced in front, the [d].
• The unvoiced consonant [s] is therefore next to the voiced consonant [d],
• The unvoiced consonant [s] will affect the pronunciation of the voiced consonant [d],
• The consonant [d] loses its voice and is pronounced [t],
• “au-dessus” is pronounced [otsy].

trente-deux

• The voiced consonant [d] will affect the pronunciation of the unvoiced consonant [t],
• The consonant [t] earns its voice and is pronounced [d],
• We must pronounce a sound [d] a little louder than usual,
• trente-deux is pronounced [tʁɑ̃d:ø].

The pair [s]/[z]

Assimilation allows the unvoiced consonant [s] to gain its voice and be pronounced [z]. On the other hand, the voiced consonant [z] may lose its voice and become pronounced [s]. Below are two examples.

Plus d’eau

• The voiced consonant [d] will affect the pronunciation of the unvoiced consonant [s],
• The consonant [s] gains its voice and is pronounced [z],
• plus d’eau is pronounced [plyzdo].

on se décide

• In the group “we decide”, the mute e is not pronounced because we speak quickly,
• The unvoiced consonant [s] is therefore next to the voiced consonant [d],
• The voiced consonant [d] will have an impact on the pronunciation of the voiceless consonant [s],
• The consonant [s] gains its voice and is pronounced as [z],
• “on se décide” is pronounced [ɔ̃zdesid].

The pair [f]/[v]

Assimilation allows the unvoiced consonant [f] to gain its voice and be pronounced [v]. On the other hand, the voiced consonant [v] may lose its voice and become pronounced [f].

clavecin

• In the word “clavecin”, the mute e is not pronounced because there is only one consonant pronounced in front, the [v].
• The unvoiced consonant [s] is therefore next to the voiced consonant [v],
• The unvoiced consonant [s] will affect the pronunciation of the voiced consonant [v],
• The consonant [v] loses its voice and is pronounced [f],
• “clavecin” is pronounced [klafsɛ̃].

lave-toi

• The unvoiced consonant [t] is next to the voiced consonant [v].
• The unvoiced consonant [t] will influence the pronunciation of the voiced consonant [v],
• The consonant [v] loses its voice and is pronounced [f],
• “lave-toi” is pronounced [laftwa].

The pair [ʃ]/[ʒ]

In assimilation, the unvoiced consonant  [ʃ] can gain its voice and be pronounced [ʒ]. On the other hand, the voiced consonant [ʒ]may become pronounced [ʃ].

projeter

• In the verb “projeter”, the silent e is not pronounced because there is only one pronounced consonant in front, the [ʒ].
• The unvoiced consonant [t] is therefore next to the voiced consonant [ʒ],
• The unvoiced consonant [t] will influence the pronunciation of the voiced consonant [ʒ],
• The consonant [ʒ] loses its voice and is pronounced [ʃ],
• “projeter” is pronounced [pʁɔʃte].

je pense

• In the segment “je pense”, the mute e is not pronounced because we speak rapidly.
• The unvoiced consonant [p] is therefore next to the voiced consonant [ʒ],
• The unvoiced consonant [p] will influence the pronunciation of the voiced consonant [ʒ],
• The consonant [ʒ] loses its voice and is pronounced [ʃ],
• “Je pense” is pronounced [ʃpɑ̃s].

The pair [p]/[b]

When there is sound assimilation, the unvoiced consonant [p] can gain its voice and be pronounced [b]. Whereas, the voiced consonant [b] can lose its voice and become pronounced as [p].

subtil

• The unvoiced consonant [t] is therefore next to the voiced consonant [b].
• The unvoiced consonant [t] will influence the pronunciation of the voiced consonant [b],
• The consonant [b] loses its voice and is pronounced [p],
• “subtil” is pronounced [syptil].

observer

• The unvoiced consonant [s] is therefore next to the voiced consonant [b].
• The unvoiced consonant [s] will influence the pronunciation of the voiced consonant [b],
• The consonant [b] loses its voice and is pronounced [p],
• “observer” is pronounced [ɔpsɛʁve].

The pair [k]/[g]

In assimilation, the unvoiced consonant [k] can gain its voice and be pronounced [g]. On the other hand, the voiced consonant [g] may become pronounced [k].

anecdote

• The voiced consonant [d] is next to the unvoiced consonant [k].
• The voiced consonant [d] will affect the pronunciation of the voiceless consonant [k],
• The consonant [k] gains its voice and is pronounced [g],
• “anecdote” is pronounced [anɛgdɔt].

sac de riz

• In the “sac de riz” segment, the mute e is not pronounced because we speak quickly.
• The voiced consonant [d] is next to the unvoiced consonant [k],
• The voiced consonant [d] will influence the pronunciation of the unvoiced consonant [k],
• The consonant [k] gains its voice and is pronounced [g],
• “sac de riz” is pronounced [sagdəri].

A video on assimilation: definition and examples

To review all this information, I suggest you watch this video, in which I explain everything you need to know about sound assimilation in French.