Hi,in my opinion,Vietnamese is a rich language which is influenced by lots of language through history,especially Chinese.Lots of foreign people have problems with Vietnamese when they learn it,such as:their speaking skill,grammar or listening.I think this is just a common thing.Don’t worry about that because words in Vietnamese is quite complicated.There are lots of words that have similar meaning ,but they have different meaning.This is depended on different areas.Beside ,there are lots of words that have the same tone but their meaning is complete different .For instance we call “đường”mean “sugar”,but otherwise”đường “ mean “the road”.The pronunciation of English is different Vietnamese too.When we speak english, we usually have the final syllable,but Vietnamese is not.Language is very large,so I think when u good at it is when u can use it to tell with people fluently.U can improve ur Vitetnamese by lots of way :talking with native people,read newspaper,so on,…Certainly, my answer is yes,because I see lots of foreign people can speak Vietnamese well.In the VTV6 of my country have an MC, Joe.He is not vietnamese,he is from Canada, but he always appear and speaks vietnamese very well Haha!! If u have any problems,feel free to ask me too.I always welcome any question.:))Hope u have lots of lucky and successes in ur learning.