Fricatives
Fricatives are articulated with a less extreme degree of constriction than stops and plosives: close approximation.
Fricatives are produced by bringing together two articulators to the point where the airflow is not quite fully blocked – leaving enough of a gap for air to escape, but as the articulators are so close together that audible friction is created as the air passes through.
There are nine fricative consonants in English:
i. voiceless labio-dental fricative [f]
created by bringing the lower lip close to the upper teeth in a constriction of close approximation, without vibration of the vocal cords
e.g. [f] in fin
ii. voiced labio-dental fricative [v]
created by bringing the lower lip close to the upper teeth in a constriction of close approximation, with vibration of the vocal cords
e.g. [v] in van
iii. voiceless dental fricative 
created by bringing the tip of the tongue into a constriction of close approximation with the upper teeth, without vibration of the vocal cords
e.g. in thin
iv. voiced dental fricative 
created by bringing the tip of the tongue into a constriction of close approximation with the upper teeth, with vibration of the vocal cords
e.g. in this
v. voiceless alveolar fricative [s]
created by bringing the tip or blade of the tongue into a constriction of close approximation with the alveolar ridge, without vibration of the vocal cords
e.g. [s] in sin
vi. voiceless alveolar fricative [z]
created by bringing the tip or blade of the tongue into a constriction of close approximation with the alveolar ridge, with vibration of the vocal cords
e.g. [z] in zip
vii. voiceless palato-alveolar fricative 
created by bringing the blade of the tongue into a constriction of close approximation with the palato-alveolar region, without vibration of the vocal cords
e.g. in shp
viii. voiced palato-alveolar fricative 
created by bringing the blade of the tongue into a constriction of close approximation with the palato-alveolar region, with vibration of the vocal cords
e.g. in vision
ix. voiceless glottal fricative  [h]
created by bringing the vocal cords into a constriction of close approximation, so that friction is produced without vibration.
e.g. [h] in hit
Approximants
The least radical degree of constriction occur when the articulators come fairly close together, but not sufficiently close together to create friction
This kind of stricture is called open approximation and consonants produced in this way are called approximants
The first sound in yes – transcribed as [j] (e.g. /jes/) is an approximant
[j] is produced by bringing the front of the tongue close to the hard palate.
Although the sides of the tongue are in constriction of complete closure with the upper gums, the air escapes along a central groove in which the front of the tongue is not close enough to the hard palate to create friction
Approximants are normally voiced, and [j] is described as a voiced palatal approximant
The first sound in many English speakers’ pronunciation of rip, rope, rat …
– transcribed as 
is an approximant
It is produced by bringing the blade of the tongue into a constriction of open approximation with the alveolar ridge
This approximant – is referred to as an alveolar approximant
As with [j], the sides of the tongue form a constriction of complete closure with the gums at the sides of the mouth, but the air escapes along a central groove without creating friction
For most speakers (and in varying degrees, depending on the accent), the tongue body is somewhat retracted when is uttered; and is therefore often described as a post-alveolar approximant, but ‘alveolar approximant’ will suffice for our purposes
The first sound in wet – transcribed as [w] (e.g. /wet/) is also an approximant
In producing this sound, the lips form a constriction of open approximation; there is no friction produced
But, the articulation of [w] is more complicated than that of [j], since [w] also involves another articulation, between the back of the tongue and the velum (i.e. a velar articulation)
Therefore [w] is referred to as a labio-velar approximant
Central Vs Lateral
In discussing the alveolar approximant alveolar approximant , we said that the air escapes along a central groove (of the tongue in this case, the same kind of groove can be formed by the lips)
This is true of all the fricatives and approximants discussed so far
However, it is possible to produce fricatives and approximants in which this is not the case
e.g. the first sound 
in lift
in producing this sound, the centre or the blade of the tongue forms a stricture of complete closure with part of the alveolar ridge, but the articulation which ‘counts’ is that between the sides of the tongue and the alveolar ridge
Since the sides of the tongue form a constriction of open articulation with the alveolar ridge, and vocal cords vibrate but no friction is created this sound transcribed as , is referred to as a voiced alveolar lateral approximant
Since English fricatives and approximants are typically central, the term ‘laterals’ are used to refer to lateral approximants and the term ‘central’ is omitted in describing central fricatives and approximants
The sounds and are quite similar: both are approximants, both are voiced, both are alveolar
The principal difference is that is lateral and is central
Taps and Trills
We have noted that, for a great many speakers of English, the sound at the beginning of words such as rat, rope, reap – is a post-alveolar approximant –
The same is true of the sound which occurs after stops in words such as prude, true, creep …
However, some speakers utter, not an approximant, but a sound which is very similar to a stop of very short duration
During the articulation of this sound, the blade of the tongue comes into a momentary constriction of complete closure with the alveolar ridge
This sound transcribed as 
, is referred to as a voiced alveolar tap (or flap)
This also the sound that many American speakers have instead of [t] and [d] in words such as Betty, witty, rider, heady …
Speakers of certain accents of English may utter neither nor in words like rat, rope, reap, prude, true, creep … but a sound referred to as a voiced alveolar trill
Trills are produced by holding one articulator (e.g. blade of the tongue) next to the other (e.g. alveolar ridge) in a constriction of complete closure, but without the same muscular pressure as in a stop
The result is that air pressure builds up behind the closure and forces it open; the air pressure then reduces, and the muscular pressure again creates a constriction of complete closure
This sequence may be repeated in quick succession, producing, in this case an alveolar trill – [r]; but this is relatively rare in most English accents
Secondary Articulation
We have said that the lateral approximant is alveolar
However, laterals may also be produced with an additional articulation, such as one formed between the back of the tongue and the velar (i.e. velar articulation)
When this happens, the alveolar articulation is distinguished as the primary articulation and the velar articulation as the secondary articulation
Where a secondary articulation is velar, this process is referred to as velarization: it is said that the lateral is velarized
The velarized lateral approximant is transcribed using the velarization diacritic – 
This sound is often referred to as ‘dark l’
Where a secondary articulation is palatal, this process is referred to as palatalization: it is said that the lateral is palatalized
The palatalized lateral approximant is transcribed using the palatalization diacritic – 
The term ‘clear l’ is often used to refer to or
Affricates
Affricates are produced with a constriction of complete closure followed by a release phase in which friction occurs.
There are two affricates in English 
and 
– voiceless palato-alveolar affricate
– voiced palato-alveolar affricate
