Language usage is a matter of expressive craft and choice in both speaking and writing. While students need to know the rules of English, they must also know how to play with language in order to communicate artfully as they consider their purpose and audience. The Iowa Core clearly states that “students must gain control over many conventions of standard English grammar, usage, and mechanics as well as learn other ways to use language to convey meaning effectively” (pg. 33).

The Iowa Core also indicates that language is to be taught in an integrated model of literacy (pg. 4). While the language standards are separated out for clarity, it is the intent that they be taught within reading, writing, speaking and listening rather than in isolation. This aligns with over 50 years of research that shows grammar, usage and spelling are best taught within authentic literacy experiences.
The University of North Carolina School of Education provides this guidance on the teaching of conventions.

Conventions of Standard English