The British dark L is a vocalised L. That means the L has become a vowel. The dark L is in 3 forms: 1. "a schwa followed by a /u/", as in "total", "mail"; 2. a /u/, as in "bull"; or 3. a /o/, as in "doll". (For 2 & 3, the vocalised dark L is turned into a vowel similar to the preceding vowel, usually pronounced without lip rounding.) For the dark L, the tongue tip doesn't touch the alveolar ridge. If it does, it is not a dark L but a light L. For the light L, the tongue tip touches the alveolar ridge.
At 2:05, the tongue tip touching the alveolar ridge is unnecessary. It is an affectation when demonstrating the pronunciation. In real life, people don't do the touching, especially in British English.
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The British dark L is a vocalised L. That means the L has become a vowel.
The dark L is in 3 forms:
1. "a schwa followed by a /u/", as in "total", "mail";
2. a /u/, as in "bull"; or
3. a /o/, as in "doll".
(For 2 & 3, the vocalised dark L is turned into a vowel similar to the preceding vowel, usually pronounced without lip rounding.)
For the dark L, the tongue tip doesn't touch the alveolar ridge. If it does, it is not a dark L but a light L.
For the light L, the tongue tip touches the alveolar ridge.
Allophones of l and r are vocalic ones, which I discuss in my book based on which the lecture is.
Light L: the tongue tip touches the alveolar ridge.
Dark L: the tongue tip doesn't touch the alveolar ridge.
Actually you are right with the dark l pronunciation. It seems impossible to touch the ridge.
At 2:05, the tongue tip touching the alveolar ridge is unnecessary. It is an affectation when demonstrating the pronunciation.
In real life, people don't do the touching, especially in British English.
Thanks. It is based on the American accent.