Q&A: In what way is the first line of the Bible mistranslated in English?

(Full question:) In the first minutes of this talk, Chomsky mentions that the first line of the Old Testament is mistranslated grammatically because of the Masoretic editors putting in the wrong vowels and that it should be obvious to people who know Hebrew. What other vowel form is available for /berešít bará/?

He’s probably referring to the fact that the word בראשית is vocalised בְּראשית be-reshit (with a shva), which technically means “In a beginning”, instead of בַּראשית ba-reshit (with a pataḥ—the contraction of the prefixes be– and ha–), which you might expect based on the translation “In the beginning”  to make it “In the…”