The classification of speech sounds

1. Labial consonants are made by the lips. They may be b i l a b i a l and l a b i o – d e n t a l. Bilabial consonants are produced when both lips are active: [p]‚ [b]‚ [m]‚ [w]. Labio-dental consonants are articulated with the lower lip against the edge of the upper teeth: [f]‚ [v].
2. Lingual consonants are classified into f o r e l i n g u a l, m e d i o l i n g u a l and b a c k l i n g u a l.
Forelingual consonants are articulated with the tip or the blade of the tongue. They differ in the position of the tip of the tongue. According to its work they may be:

• 
  a p i c a l, if the tip of the tongue is active: [t]‚ [d]‚ [s]‚ [z]‚ [∫]‚ [ʒ]‚ [Ө]‚ [ð]‚ [ʧ]‚ [ʤ]‚ [n]‚ [l];
  

• 
  d o r s a l, if the blade of the tongue takes part in the articulation; the tip is passive and lowered. In English there are no dorsal consonants;
  

• 
  c a c u m i n a l, if the tip of the tongue is at the back part of the teeth ridge, but a depression is formed in the blade of the tongue: [r].
  

According to the place of obstruction forelingual consonants may be:

• 
  interdental;
  
• 
  dental;
  
• 
  alveolar;
  
• 
  post-alveolar;
  
• 
  palato-alveolar.
  

I n t e r d e n t a l consonants or interdentals are made with the tip of the tongue projected between the teeth: [Ө]‚ [ð].
D e n t a l consonants or dentals are produced with the blade of the tongue against the upper teeth: e.g. the Russian [т], [д].
A l v e o l a r consonants or alveolars are articulated with the tip against the upper teeth ridge: [t]‚ [d]‚ [s]‚ [z]‚ [n]‚ [l].
P o s t – a l v e o l a r consonants or post-alveolars are made when the tip or the blade of the tongue is against the back part of the teeth ridge or just behind it: [r].
P a l a t o – a l v e o l a r consonants or palato-alveolars are made with the tip or the blade of the tongue against the teeth ridge and the front part of the tongue raised towards the hard palate, thus having two places of articulation or foci: [ʧ]‚ [ʤ]‚ [∫]‚ [ʒ].
Mediolingual consonants are produced with the front part of the tongue. They are always p a l a t a l. Palatals are made with the front part of the tongue raised high to the hard palate: [j].
Backlingual consonants are also called velar, because they are produced with the back part of the tongue raised towards the soft palate: [k]‚ [g]‚ [ŋ].
3. The glottal consonant [h] is articulated in the glottis.