Front

in vain

Back

むだに/むなしく for nothing / to no purpose

Front

at work

Back

仕事中で/働いて

Front

under way

Back

進行中で in progress

Front

by chance

Back

偶然に/たまたま by accident / accidentally

Front

on purpose

Back

故意に/わざと intentionally / deliberately

Front

on the go

Back

忙しく働いて/活動して very busy[active]

Front

in turn

Back

(代わって)今度は

Front

in advance

Back

前もって/あらかじめ ahead of time / beforehand

Front

once in a while

Back

ときどき from time to time / on occasion

Front

out of order

Back

故障して