Grammar Ninja

Grammar Ninja is an online game that tries to make us aware of the different parts of speech in the language through a number of recognition activities.

It is divided into three levels of difficulty, each of which foucsing on different parts of speech:

Basic: Nouns and verbs
Skilled: Nouns, verbs, pronouns, articles, adjectives and adverbs
Master: All parts of speech

H/T to DDeubel.