Many Russian consonants come in "hard"/"soft" pairs, and the quality is expressed in print by the letter used to represent the vowel. That is, the letters in these pairs a/я, э/е, о/ё, у/ю are all pronounced the same! (the pair ы/и is a slightly different issue). It is the preceding consonant that is pronounced differently. Except for word-initial position, where both members of the pairs can occur, in which case you get the "y-glide" as in English "yet" occurring before the "soft" member of the pair (the second one in my examples). So the word for Christmas tree ёлка is phonemically represented with this y-glide (a semivowel) as /jólka/, but the word тёлка has an initial palatalized ("soft") consonant: /t'о́lka/