表現 Break: 二足のわらじを履く

So every once in a while, the 1級 book will throw an expression at us that we ought to be aware of.

This is one of those.

Can you guess which grammar point it complements?

二足の草鞋を履く
にそく　の　わらじ　を　はく

To wear two different pairs of straw sandals.

Now... I was initially confused about why you would ever wear sandals, or any shoes for that matter, on only ONE of your feet, but then someone pointed out that 足 is actually the counter for PAIRS of legs. 靴一足 is one pair of shoes, which makes much more sense.

My book explains that this is used for someone who's working two jobs at the same time, and gives the example,　「姉は日本人に英語を教えるかたわら、外国人に日本語を教える仕事もしている。」

But, when I looked into the origins of this weird little phrase, I found that it is actually should be used in cases where those two different occupations should be incompatible. 「二足に草鞋を履く」 was coined during the Edo Era, to talk about constables (捕吏） who moonlighted as professional gamblers　or vice versa.
Click the pic on the right for some 江戸時代博打.

While it seems like this information might limit the ways that you can use this phrase, remember that Japanese society generally does not condone holding more than one job, so while being an eikaiwa teacher for two different companies probably wouldn't earn you a ｢二足に草鞋」 admonition, being a teacher by day and a bartender by night would definitely qualify.

Teacher and a porn star? (Despite what the vast quantities of video evidence seem to suggest...) FROWNED UPON.