To Translate the words in Magento:
app/design/frontend/Package_Name/Theme_Name/i18n/en_US.csv file and add the following rows:
"Add to Cart", "Purchase"
"Add to Compare", "Compare"
"Add to Wish List", "Wishlist"
Then run :
php bin/magento setup:static-content:deploy -f
change directories according to your theme
