Language(s) of Jesus

To follow up on Bob Kraft's interesting comment, might one argue
that the Aramaic/Hebrew phrases quoted in Jesus's words in the
gospels (talitha kum, ephphatha, etc.) were transliterated
*because* they were unusual in his (normally Greek) speech?  I
wouldn't want to push this hard unless there were other reasons
to think Jesus spoke Greek (too much speculation for me!), but it
makes as much sense as other explanations for these phenomena.
George Aichele
Adrian College