 As described in the introduction, LL(1) parsers recognize languages that have LL(1) grammars, which are a special case of context-free grammars; LL(1) parsers cannot recognize all context-free languages.The LL(1) languages are a proper subset of the LR(1) languages, which in turn are a proper subset of all context-free languages.In order for a context-free grammar to be an LL(1) grammar, certain conflicts must not arise, which we describe in this section.