In one of the transtlations for Wheelock ch. 7, the book gives as translation for Homini litteras dabunt "They will give a letter to the man". I came up with "They will give the man the letter".
Aside from word order, the difference between the book's translation and my translation is the definite article "the" vs. the indefinite article "a".
In earlier chapters the advice was to insert a the or an a as context required. In this case either seems ok, so I went with "a". I have noticed that the book and I differ in "the" and "a" often so my question is: is there some rule I should be following here?