Find partial match with textsearch query

I have the following query that I did hard looking on this site: SELECT * FROM renns WHERE ( to_tsvector('english', coalesce(numar_admin, '')) || to_tsvector('english', coalesce(nume_strada, '')) || to_tsvector('english', coalesce(nume_prenume, ''))|| to_tsvector('english', coalesce(bloc, '')) || to_tsvector('english', coalesce(apartament, '')) ) @@ plainto_tsquery('english', '$q') It works if I write in the variable $q all the text that appears in one of the columns present in the query. For example: cherry I would like to write only: cher and return all rows fields in which it finds this string: "cher".