"He bought a new tree and he put it in the garden."
Translation:Cheannaigh sé crann nua agus chuir sé é sa ghairdín.
Isn't it considered more traditional to put the e at the end of the sentence?
Yes, it is. Though it's not wrong, per se, to put it where it currently is. Most natives would have it at the end, though.
Only Cheannaigh sé crann nua agus chuir sé é sa ghairdín is considered right in the pick & choose part - picking Cheannaigh sé crann nua uisce chuir sé sa ghairdín é. penalizes you