know the first thing about



not know the first thing about something

to not know anything about a particular subject I don't know why you're asking Rob, he doesn't know the first thing about classical music.
See also: first, know, thing

Common Names:

NameGenderPronouncedUsage
Madelon-Dutch
Octave-French
MaikeMIE-kə (German)Frisian, German
FredrickFRED-rikEnglish
Vladan-Serbian, Czech, Slovak
Hayatohah-yah-toJapanese