Usages of erfiðari
Framhaldið verður líklega erfiðara, en við munum hafa lært mikið.
The continuation will probably be more difficult, but we will have learned a lot.
Þessi æfing er erfiðari en æfingin í gær.
This exercise is more difficult than the exercise yesterday.
Elon.io is an online learning platform
We have an entire course teaching Icelandic grammar and vocabulary.