Words that can't be practiced?
At the moment, I'm almost up to the second keyhole in learning. I've got a few words (Mainly in prepositions and conjunctions) that appear in my vocabulary but can't be practised at all. Basically, if I click on the word, and try to "practice this word" it simply takes me back to the home screen where the skill tree is. I've attached an image below.
Does this mean I haven't truly "been introduced" to the word yet and it will appear further down the track? Or is this a beta bug?