Open Adobe Acrobat Pro DC and ensure you are signed in.

Remember your adobe password is different to your normal login, and will normally require a symbol.

Select the form you've scanned and select edit PDF.

Select the "Tools" tab and click "Prepare form"

Save this file

You and your students can now fill in this form.

How to write paragraphs in a fillable form.

Method 1: Without Lines

Go to your word document and manually delete all lines from the paragraphs.

Re-Convert your word document into a fillable form.

Go to Tools -> Prepare Form

Add a Text Field

Click and drag your text field to fit the desired area. Give it a unique name.

Double click on your text field and navigate to the options tab.

Ensure Multi-Line is enabled. Also allow Rich Text Formatting.

Test is by using the fill and sign section.

Method 2: With Acrobat line text fields.

Using acrobat, navigate to the "Edit PDF" tab. 

Delete all black lines in the document. You will be left with multiple text fields as shown below in Personal Attribute Two.

Go back into Prepare Forms, double click on each individual text box and ensure Multi-line and Allow Rich Text Formatting is enabled.