BBC ESL-to, for, so that

I take the challenge to, for, so that. I had 6 right answers, and I had 2 mistakes.

The right answer is..

I bought a lovely new dress-to wear to the party.
David worked really hard-to pass the final exam.
I gave my teacher a big bunch of flowers-to say 'Thank you'.
I got up early-so that I could be first in the queue when the shop opened.
My son won a prize at school-for painting the best picture.
I ordered an extra loaf of bread-so that we'll have enough for the weekend.

And The wrong answer is..
-A small notebook is useful-for making important parts of documents.(X)
A small notebook is useful-for writing down new vocabulary.(O)

-Highlighter pens are great-for writing down new vocabulary.(X)
Highlighter pens are great-for making important parts of documents(O)
↑I think it is more make sense. It is more logical.

And I acknowledged that preposition 'to' always needs verb or verb+~ing