if u want to achieve fluency, u should practise the language whatever u r learning.if u r learning english u can chat with the somebody in english.u should watch english programs on the tv.read lots of english articles and start discussions. like lot of things u can do.if u are doing full time practise that is better than a part time practise.but if time is not there we should go ahead with part time.but it will take more time than the part time to get the fluency.
Part-time learning is better actually, like i use it to understand whenever there is any doubt about some sentance..
Even italki gives opportunity to make friends so that you can start conversation by chatting or skype.
It's finally upto you how much time you are giving for learning language.
my suggestion is part time learning could not achieve well
full time learning is much efficient than part time