For the lexical queries (text search and word frequency query) you can customize the language settings so that NVivo detects the words in the correct language and excludes words based on the stop-word list.

Supported languages

NVivo supports several text content languages (e.g. English, Spanish, German, Japanese etc.) for which it has pre-defined stop-words lists and you can also switch between different settings in the lexical queries like stemmed words or synonyms.

Other languages

If you are working with data in a different language, you will have to define the text content language as "Other" and customize your settings, prior to running any lexical queries. Therefore, in your open project go to “File”, choose “project properties” and switch the “text content language” to “Other” (the default option is “English (US)”. Then, if you run a text search (in which you can also choose which sources/cases to include in the search, in case you work with multiple languages) you can search for different terms and put the slider on “exact matches”. In the project properties next to "text content language" you will also find a button to open the stop-words list which you can customize for every project.

More information

Please find more information here:http://help-nv11.qsrinternational.com/desktop/procedures/run_a_text_search_query.htm 

and for special text search queries here:
http://help-nv11.qsrinternational.com/desktop/deep_concepts/special_characters_and_operators.htm