According to line dictionary, both of these mean 'language'. From looking at the examples list, 语言 seems to be a more literal translation of 'language', for example if one wanted to say "Chinese is my favourite language", I think one could write this as 中语是我最喜欢的语言. On the other hand 言语 seems to be used when referring to someone's 'use of language' as opposed to languages from different countries. For instance if one wanted to translate "he used aggressive language" one would use 言语.
Is this the right kind of idea?