Use Free Text Queries if you want to enter queries using natural language. Index Server will examine your query, extract nouns and noun phrases and construct a query for you.  With free text queries you can enter any text you want, from a proper question, to a string
of words and phrases, without worrying about the query language. For example, if you type in the following query:  "How do I use the Index Server administration snap-in?"  Index Server will create a query for you automatically and begin the search. Note that when
you're using free text queries, the regular query language features are disabled and keywords such as AND, OR, and NEAR are interpreted as normal words.