Teacher Discussion Forums

Hi,
Do the 'interlanguage', 'idiosyncratic dialect' and 'performance' concepts refer the same idea?

The first two terms appear to be synonymous (though coined by different people - Selinker versus Corder), while the third term seems much more general (e.g. 'slips or "performance errors" that even a native speaker may make when tired, or drunk, etc') and not specifically related to SLA. From what I understand, one's linguistic performance is supposedly a less-than-perfect manifestation of an underlying competence.