we don't use the dictonary form of the verb.not - 書くにくい It's the masu form such as 書きにくい。そうですね？

If the verb you're using is usually in ている form, do you say ていにくい or use the base verb? Most don't make sense in ている form, but I could see saying "it's difficult to wear". 浴衣が大好きなのに学校で着にくいです sounds like it's hard to put it on at school (which may be needed after gym class), and 着ていにくいです sounds like it's hard to wear to school (either for the embarrassment factor or the difficulty in maneuvering, take your pick). But is that right?

Also, it seems like whatever is hard to [insert verb here] is supposed to be the subject of the sentence - so ハイヒールで歩きます becomes ハイヒールは歩きにくいです, yes? You might want to make that clear. And maybe change the format of the example's English translations to be more along the lines of "sandals are hard to run in" and "ramen is hard to eat with a fork." They mean approximately the same thing, but it helps remind that the subject of the sentence is what would normally be the object.

I suspected that might be the case. Thanks for the confirmation!

How do I use a する verb with this? Nothing in my head seemed to sound right. 勉強しにくい?