Primary language is spoken while secondary written?

That's not quite right. It's more accurate to say that language is spoken and written, and that reading and writing are typically learned as secondary skills after speaking and listening.

Here's why:

* Spoken language is primary: Humans are born with the capacity to learn language, and most infants begin to understand and produce spoken language before they can read or write.

* Written language is secondary: Writing systems are developed later, and learning to read and write requires explicit instruction.

While we can't say that spoken language is inherently *better* or *more important* than written language, it's safe to say that spoken language comes first in human development and is the foundation upon which written language is built.