*
* 2. the ->buf member is a byte array that has at least ->len + 1 bytes
* allocated. The extra byte is used to store a '\0', allowing the ->buf
- * member to be a valid C-string. Every strbuf function ensure this
+ * member to be a valid C-string. Every strbuf function ensures this
* invariant is preserved.
*
* Note that it is OK to "play" with the buffer directly if you work it