tend是趋于的意思，而look after则是照顾的意思，区别可以从以下例子看出：

The COVID-19 pendamic tends getting worse, local government will easy the lockdown soon, we have to look after ourselves. COVID-19 疫情趋于恶化，当地政府很快就会放松封锁，我们必须照顾好自己。