Ukrainian students of English sometimes replace the English [t, d] by the corresponding Ukrainian sounds. For the English consonants [t, d] the tip (not the blade) of the tongue should be pressed against the alveolar ridge (not the upper teeth). When they are pronounced the students should be careful to make them strong and aspirated.
Ukrainian learners of English may carelessly pronounce [w] instead of [v]. This mistake is a phonological one. To avoid it the mirror should be used to make sure that the upper lip is out of the way.
Learners of English sometimes pronounce [f, v] instead of [θ,ð] because there are no similar sounds in Ukrainian. To avoid it the lower lip should be kept out of the way. Sometimes [t, d] may be heard instead of [θ,ð]. To get rid of the mistake the tip or the blade of the tongue should not be pressed either against the teeth ridge or the teeth. If [s, z] are heard remember that the tip should be against the edge of the upper teeth.
Very often Ukrainian learners of English replace the English [ŋ] by [n] because there is no similar sounds in Ukrainian. Not to make this mistake you should raise the back of the tongue to the soft palate. The tip of the tongue should not rise at all being kept at the lower teeth. A mirror may help to check the position of the tongue.
Some speakers tend to replace the bilabial sonorant [w] by the English labio-dental, fricative [v]. Not to make the mistake keep the lips well rounded when [w] is pronounced; there should be a glide towards the following vowel.
Ukrainian learners often replace the English post-alveolar sonorant [r] by the Ukrainian alveolar rolled [р]. To avoid this mistake they should move the tip of the tongue to the back of the alveolar ridge and keep it tense at some distance from it so that no tapping of the tongue could be made when the air goes through the passage.
The Ukrainian consonants [п, б] are mainly pronounced in the same way, but the lips are not so tense as for the English [p, b].
The Ukrainian consonants [т, д] are produced with the blade of the tongue against the back of the upper teeth. They are dental, while the corresponding English sounds are apical alveolar and the Ukrainian consonant [т] is not aspirated.
The Ukrainian consonants [к, ґ] are produced in a similar way as English corresponding sounds, but the breath effort for the Ukrainian [к] is not so strong as for the English [k] which is aspirated.