Have you ever wondered why we say 'impossible' with an M, but 'intolerant' with an N? Or why 'in front' sounds like 'im front' in natural speech? This is called nasal place assimilation, a natural process where nasal sounds change to match the consonant that follows them.
What Is Nasal Place Assimilation?
Nasal place assimilation occurs when a nasal consonant (/n/, /m/, or /ŋ/) changes its place of articulation to match the following consonant. This happens because it's easier and more efficient to keep your tongue or lips in the same position for consecutive sounds.
English has three nasal sounds:
- /m/ - bilabial (both lips): make, summer
- /n/ - alveolar (tongue at ridge): nose, sunny
- /ŋ/ - velar (back of tongue): sing, think
The Three Types of Assimilation
1. N → M (Before Bilabial Consonants: /p/, /b/, /m/)
When /n/ comes before /p/, /b/, or /m/, it becomes /m/:
Across word boundaries:
- in public → /ɪm ˈpʌblɪk/
- ten boys → /tem bɔɪz/
- in between → /ɪm bɪˈtwiːn/
- one more → /wʌm mɔːr/
2. N → ŋ (Before Velar Consonants: /k/, /g/)
When /n/ comes before /k/ or /g/, it becomes /ŋ/ (the 'ng' sound):
Across word boundaries:
- in case → /ɪŋ keɪs/
- ten girls → /teŋ ɡɝːlz/
- on camera → /ɑŋ ˈkæmərə/
- in good time → /ɪŋ ɡʊd taɪm/
3. N → ɱ (Before Labiodental Consonants: /f/, /v/)
When /n/ comes before /f/ or /v/, it becomes labiodental [ɱ] (made with upper teeth and lower lip):
Across word boundaries:
- in front → /ɪɱ frʌnt/
- ten feet → /teɱ fiːt/
- on vacation → /ɑɱ veɪˈkeɪʃən/
- seven visitors → /ˈsevəɱ ˈvɪzɪtɚz/
Why Does This Happen?
Assimilation is a natural result of speech efficiency. When we speak quickly:
- Moving the tongue or lips takes time and effort
- Keeping articulators in the same position is easier
- The nasal 'anticipates' the upcoming consonant
This process is unconscious for native speakers and happens automatically in connected speech.
Assimilation Summary Table
| Following Sound | N Becomes | Example | Pronunciation |
|---|---|---|---|
| /p/, /b/, /m/ | /m/ (bilabial) | input | /ˈɪmpʊt/ |
| /k/, /g/ | /ŋ/ (velar) | income | /ˈɪŋkʌm/ |
| /f/, /v/ | /ɱ/ (labiodental) | confirm | /kəɱˈfɝːm/ |
| /t/, /d/, /s/, /z/, /n/, /l/ | /n/ (no change) | intend | /ɪnˈtend/ |
This Also Happens in Spanish!
Good news for Spanish speakers: Spanish has similar nasal assimilation patterns!
- un peso → [um ˈpeso]
- en casa → [eŋ ˈkasa]
- un favor → [uɱ faˈβor]
So this process should feel somewhat natural to you. The key is recognizing that it happens in English too, especially across word boundaries in connected speech.
Practice Phrases
Practice these common phrases with nasal assimilation:
N → M
- in Paris /ɪm ˈpærɪs/
- one more time /wʌm mɔːr taɪm/
- ten percent /tem pɚˈsent/
- on purpose /ɑm ˈpɝːpəs/
N → ŋ
- in common /ɪŋ ˈkɑːmən/
- one cup /wʌŋ kʌp/
- main goal /meɪŋ ɡoʊl/
- in college /ɪŋ ˈkɑːlɪdʒ/
N → ɱ
- in fact /ɪɱ fækt/
- eleven fifty /ɪˈlevəɱ ˈfɪfti/
- in favor /ɪɱ ˈfeɪvɚ/
- own voice /oʊɱ vɔɪs/
Listening Practice Tips
- Don't expect to hear a clear N: Before /p/, /b/, /k/, /g/, /f/, /v/, the N will sound different
- Listen for the pattern: Once you know about assimilation, you'll start hearing it everywhere
- Practice connected speech: Don't pause between words; let the assimilation happen naturally
Understanding nasal assimilation helps you both speak more naturally and understand native speakers better. It's a subtle but important feature of fluent English!