know one's ABCs
знать основное о чём-либо, иметь базовые знания
The woman in the library knew her ABC's and could quickly give me the information I needed.
Другие идиомы:
- know better (than to do something)
- know (something) inside out
- know a trick or two
- know where (someone) stands on (something)
- know (something) in one's bones
- know (something) from memory
- know (something) only too well
- know (something) by heart
- know (someone) by sight
- know which is which
- know the score
- know when one is not wanted
- know one's stuff
- know all the tricks of the trade
- know the ropes