13. Match classificatory principles and groups of minimal pairs given below (the consonants opposed initially).

1. labial bilabial vs. lingual backlingual	__pin-bin, pack-back, tie-die
2. forelingual alveolar vs. forelingual postalveolar	__fee - wee, fell - well
3. voicelss fortis vs. voiced lenis	__ pole - coal, bait - gait
4. labial labio-dental vs. labial bilabial	__ pity - city, pay - say, pail - sail
5. occlusive vs. constrictive	__ sob - rob, sole - role, sight - right

14. What minimal distinctive feature (or features) makes these oppositions phonologically relevant?

cap-cab	sent-send	leak-league	voiceless fortis vs. voiced lenis
pee - fee	tie - sigh	do - zoo
till -chill	day-jay	dare-chair
save-shave	presser-pressure	mass-mash

15. Define the common features and the distinctive features of the phonemes which are opposed.

Opposed phonemes	Common features	Distinctive features
[p]-[d] pen-den	occlusive-occlusive	labial-lingual fortis voiceless-lenis voiced
[r]-[l] rain-lain
[f]-[v] leaf-leave
[k]-[ŋ] back-bang
[t]-[h] tea-he
[k]-[b] cat-bat
[d]-[l] ward-wall
[w]-[n] whale-nail
[p]-[ð] pen-then
[h]-[s] hell-sell
[b]-[l] bet-let

16. Read about the types of the allophones and illustrate each of them with your own examples.

Since every phoneme can be realized through several allophones, the need arises for their classification. First allophones are divided into principal/typical and subsidiary/ secondary/subordinate.

The principal allophones of a phoneme are free from the influence of the neighbouring sounds and they are most representative of the phoneme as a whole.

The subsidiary allophones of a phoneme are subdivided into 2 groups: combinatory and positional. Combinatory allophones are those which appear as a result of the influence of the neighbouring speech sounds (assimilation, adaptation, accommodation), e.g. dental variants of the alveolar phonemes /t, d, s, z, 1, n/ are due to the influence of the following interdental sounds [θ], [ð]; the mid-open [e] becomes more open when followed by the dark [ł]:

tell - hell - sell vs. bet - let - set

Positional allophones occur in certain positions only. They appear traditionally, according to the orthoepic norms of the language rather than because of the observable influence of the neighboring sounds:e.g. see [si:]l-seed [si:d]-seat [si:t]

Principal and subsidiary allophones are of great theoretical and practical importance. The principal variant of each phoneme is included in the classification of the phonemes of a language and described to language learners and in textbooks intended for them. The wrong choice of the subsidiary allophones causes a language learner's foreign accent.

Arbitrary allophones appear as a result of idiolect or dialect (in the speech of a single person or a group of people): loch [x]; sure [ɔǝ].