highlight text by page user
I'm working on an educational website for reading strategies where I would like to have the possibilty for the user to highlight text and the possibilty to check their highlighted answers.
User task: Mark all the cause and effect connectors (because, so, therefore etc) in the text.
Now I want the user to take the mouse and go over the text and mark all these connectors in the text. After marking the entire text the user will get feedback for his correct and incorrect answers and a possibilty to correct his mistakes.
If the user marks in the sentence "He got hurt, because he fell of his bike." the word 'because' I would like somewhere else on the page be written that he did this correctly. If he would mark the word 'hurt' I would like the user to get a feedback saying that this answer is incorrect.
Is this possible with simple html or do I need something else. If I need something else what do I need and maybe there is already a ready to use script for this.