Unilingual

The opposite of bilingual. If you only speak one language, you're unilingual.

40% of the people in the world are unilingual.

Unilingual by Lumby_Jack July 11, 2017

unolingual 

Spanglish; a person that speaks only English and does not plan to learn or even try to learn Spanish

In an annoyed tone, she replied to her colleague who always greeted her in Spanish "I don't speak Spanish, I am unolingual"

unolingual by tofallinlovewith October 4, 2013