Here are ten questions to ask that will not put your friend in a tough spot, but will still give you some useful input on your novel:

1. At what point did you feel like “Ah, now the story has really begun!” 
2. What were the points where you found yourself skimming? 
3. Which setting in the book was clearest to you as you were reading it? Which do you remember the best? 
4. Which character would you most like to meet and get to know? 
5. What was the most suspenseful moment in the book? 
6. If you had to pick one character to get rid of, who would you axe? 
7. Was there a situation in the novel that reminded you of something in your own life? 
8. Where did you stop reading, the first time you cracked open the manuscript? (Can show you where your first dull part is, and help you fix your pacing.) 
9. What was the last book you read, before this? And what did you think of it? (This can put their comments in context in surprising ways, when you find out what their general interests are. It might surprise you.) 
10. Finish this sentence: “I kept reading because…”

Your friend is probably still going to tell you, “It was good!” However, if you can ask any specific questions, and read between the lines, you can still get some helpful information out of even the most well-meaning reader.

Source: Examiner

This is really useful advice, especially if the person you’ve shared your story with hasn’t had much/any experience critiquing. 

It does a great job of asking for a balance of both positive and negative feedback in a way that’s comfortable for both the author and reader. 

Ooh, these are excellent, and I have a hell of a time coming up with good questions to get more than a cycle of “I liked it!” “Great, what did you like about it?”

“…It was good?”