The technical details were 'over my head'. [=too complicated for me to understand]
She started to ask a question and then her voice 'tailed off'. [='trailed off']
His handwriting was so bad that we 'couldn't make heads or tails out of' it.
(..) Dialogue: Marked=..,Default,NTP,!Effect,...you could always threaten him... Dialogue: Marked=..,Default,NTP,!Effect,...with a nice pair of ears\Nto go with that tail of his. Dialogue: Marked=..,Default,NTP,!Effect,But Hagrid, we're not allowed to do magic\Naway from Hogwarts. You know that. (..)2001 Harry Potter and the Sorcerer's Stone
(..) Dialogue: Marked=..,Default,NTP,!Effect,Very curious. Dialogue: Marked=..,Default,NTP,!Effect,lt so happens that the phoenix... Dialogue: Marked=..,Default,NTP,!Effect,...whose tail feather resides\Nin your wand, gave another feather. Dialogue: Marked=..,Default,NTP,!Effect,Just one other. (..)2001 Harry Potter and the Sorcerer's Stone