Vietnamese students study grammar seriously, they work a lot on phonetics: they learn to pronounce the sounds g, d, l, l', w, w, c that are "difficult" for them; read "wow" as "ovo"; change sounds in the flow of speech in full style in accordance with the laws of the Russian language, for example at the junction of the words noisy before noisy assimilate, and noisy before sonants and in not assimilate, etc.