Should I add these versions for every keyphrase

If I want to target this keyphrase "Build Chicken Coop", should I add all of these keyphrases: "Build Chicken coop", "Build a Chicken coop", "Build Chicken coops", "build your chicken coop", or only one could be enough to target all others...

 

"build chicken coop" should cover "Build Chicken coop" and "Build a Chicken coop" and other CapitaLized/noncapitalized variations but you need to take on the variations like "Build Chicken coops", "build your chicken coop" if you're using prhrase match.

 

Better to use all version of keyword, we don't know from where vistor will search..
Also look on the costly keyword, it means more visitors are searching on that keyword..

 

Is there any point to listing all three:"buy chicken coop" (broad), "buy chicken coop" (exact), and "buy chicken coop" (phrase)?

 

Nope, broad will cover all three.

 

Hmm that's good to know, it will save me some time; I thought it mattered because I am getting different quality ratings on them.