
The Phonemic Vowel Chart (Diphthongs: gliding to /u/)
Examples:
/∂u/ as in goes, boat, throe.
/au/ as in cow, tour, doubt.{Alabi, T.A. (2009)}.
Animasaun (2000), submits that Nigerian speakers of English have greater difficulties with diphthongs than they have for monothongs. He observes that Nigeria speakers of English tend to ‘’monothongise’’ most diphthongs, e.g, eight /eit/, is pronounced as /et/ without a glide.
The English Consonant Sounds
According to Yusuf (2000), consonant sounds are produced with obstruction to the flow of air at some points in the vocal tract.
The obstruction may be complete or partial. Consonant sounds play a prominent role in forming words. It serves as the backbone of English words.
Ibileye (2000), identifies twenty-four consonant sounds in English. Certain factors, notes, Ibileye considered in describing English consonant phonemes; namely, the manner of articulation; the place of articulation and the state of the glottis whether cords are vibrating or not.
The Manner of Articulation
Manner of articulation refers to how the air stream is interfered with in the production of consonant sounds (Yusuf, 2000). He says there may be complete or partial obstruction of the air stream. English consonant phonemes are divided into obstruent and sonorant. Obstruent include; plosives/stops, fricatives and affricates. Yusuf also points out that sonorant include nasals, laterals (liquids), frictionless continuant and semi vowels(glides).These consonant sounds are characterized with musical like tone.
The Place of Articulation
Ibileye (2000), says place of articulation refers to the point in the vocal tract where articulation of a speech sound is made. In the production of the English consonant phonemes, nine points of articulation are identified: they are; bilabial, labio-dental, inter-dental, alveolar, post-alveolar, palato-alveolar, palatial, velar, and glottis.
The State of the Glottis
Animasaun (2002), says the opening between the vocal cords, is called the glottis and that the activities of the vocal cords are controlled by the glottis in the same consonant sound. He goes on to say that the glottis open and air passes through the slack vocal cords. According to him, the air is later modified in the mouth to make a sound. These voiceless sounds/f,s,r/ are thereby produced. The sounds produced when the vocal cords are brought together, tightened, thus narrowing the glottis, are known as voiced sounds. They are /b,v,z,/.