Note that this function is far from covering all grammatical possibilities. I.a. it currently doesn't support the special cases where a masculine noun gets an n or en ending attached in
the accusative, dative and genitive cases.
See also
Other spoken language functions:
add_definite_article_de(),
definite_article_de(),
definite_article_de_declined(),
n_ify(),
phrase_datetime(),
rank_nr(),
write_out_n()