Normalcy vs. normality are two different words for the exact same thing – a state of being normal. So which should we be using?
Normality is the most popular. A quick peek at this ngraph reveals that normality wins when it comes to amount of usage. You’ll also see the popularity of normalcy peaks in 1920 – which we can mostly put down to President Warren G Harding’s ‘Return to Normalcy’ campaign slogan.
And on a purely linguistic level, normality just makes more sense. Nouns ending in –cy are usually derived from adjectives ending in –t. Whereas nouns ending in -ity are derived from adjectives ending in –l (eg. personal-ity, legal-ity etc). Which makes normalcy an anomaly and normality, well, right.
However normalcy doesn’t seem to be a bastardisation of normality. It’s been in use since the eighteenth century so culling it completely seems unfair. But if you ask us, all things considered, normality trumps normalcy every time.
Whichever one you choose to back, be loyal. In cases like these consistency is your best defence from the (pavement) pedants of the world.