Is it possible to find out that users are translating your site using the browser’s built-in translator? Easy.
Add a Custom html tag with the following content:
<script>
document.addEventListener('DOMSubtreeModified', function(e) {
if ((e.target.tagName == 'HTML') &&
(e.target.className.match('translated'))) {
dataLayer.push({
'event': 'UAevent',
'eventCategory': 'Behaviour',
'eventAction': 'Google Translate',
'eventLabel': '{{Page URL}}',
'eventValue': null
});
}
}, true);
</script>
And in Universal Analytics, events will appear in the events section Behavior > Google Translate > Page URL.