Vietnamese students study grammar seriously, and they work a lot on phonetics: they learn to pronounce the sounds that are "difficult" for them – г, д, л, ль, ж, ш, ц; to read “ого” as “ово”; and in connected speech in the full style to change sounds in accordance with the laws of the Russian language, for example at word boundaries, voiced consonants before voiceless ones assimilate, and voiced consonants before sonorants and в do not assimilate, etc.