We mean that his native language, not one that he's acquired subsequently, but the one that he learned as a child, was Greek, some version of the Greek language.

我们以他的母语为依据,即他们非后天习得的,而是从小所学的语言,即是希腊语的,或是一些希腊地区的方言的

耶鲁公开课 - 古希腊历史简介课程节选

He addresses instead the English language: "Hail native Language," Milton begins, and then he proceeds to set out in his heroic couplets of iambic pentameter a map for his future career as a famous poet.

反而写了英语这门语言：,开头写道，“为本土语言欢呼吧“,然后继续写他的五音部短长格对句,这是著名诗人对未来事业的规划。

耶鲁公开课 - 弥尔顿课程节选