To enable searching with partial words eg. returning records that contain 'linux', when user queries only for "lin", you need to add following options to the sphinx.conf:

index name_idx
{
    ...
    min_infix_len = 3
    expand_keywords = 1
}

and just run the indexer.

Now it is possible to search for articles using only part of the words, eg. lin fedo will return posts associated with (among others): linux and fedora.

Inflection of words

To find texts with words in different forms then the ones used in query you need to use lemmatizer or stemmer dedicated for the language:

index name_idx
{
    ...
    morphology      = stem_en
}

Results:

References