She Isn't Chee: Keeping SH and CH Apart

The Japanese sound in 'shi' (as in 'shimasu') is acoustically close to both English 'sh' (in 'sheep') and 'ch' (in 'cheap'), which means your ear and mouth may treat them as basically the same sound. English, though, keeps them firmly apart — 'sh' is a smooth, continuous hiss, while 'ch' starts with a quick stop before the hiss, like a tiny explosion followed by air. Try this: say 'sh-sh-sh-sh' continuously for a few seconds, noticing there's no interruption, just steady friction. Then say 'ch-ch-ch-ch,' noticing each one starts with a small stop. Once you feel that difference, practice the pairs 'sheep/cheap,' 'shoe/chew,' and 'wash/watch,' going slowly back and forth. Recording yourself and playing it back is especially useful here, since your ear may need extra practice catching a distinction your native sound system never required. Two minutes on these pairs today will train both your mouth and your ear at once.