"The restaurant is near the Great Hall."
Translation:vaS'a'Daq Sum Qe'.
The -'e' focus/topic marker is only required when using a pronoun as if it were the verb "to be" connecting two nouns or connecting a noun to a location. So if we were to say "A restaurant is a building," (equating two nouns), we would use the pronoun 'oH to connect those two nouns in the sentence qach 'oH Qe''e'. Here the -'e' is required because we are using the pronoun 'oH as if it were a connecting verb.
And when using a pronoun as "to be" for a location, we might say, vaS'a'Daq 'oH Qe''e' ("The restaurant is at the Great Hall."). Again, the -'e' is required because of the 'oH pronoun being used for connection.
However, the sentence in this exercise is NOT using a pronoun to act as the verb "to be". This sentence uses an actual verb: Sum. This verb already includes the concept of "to be" within it: "to be nearby". But that doesn't mean it is following the same pattern as using a pronoun as "to be". Sun is not a pronoun, it is an actual verb. That means that the -'e' suffix is NOT required. So the sentence vaS'a'Daq Sum Qe' is correct for "At the Great Hall, the restaurant is nearby."
Note, also, that, in English, adjectives are treated much like nouns in sentences like, "The restaurant is good." But many of the English adjectives are actually verbs in Klingon and so also follow the verb pattern rather than the pronoun pattern and do not need -'e'. So, QaQ Qe' is correct for "The restaurant is good."
Here's the whole sentence that I used as a summary:
The -'e' focus/topic marker is only required when using a pronoun as if it were the verb "to be" connecting two nouns or connecting a noun to a location.
In this exercise, the use of the verb Sum does seem too match the second half of my explanation (it is being used to connect a noun to a location). However, Sum is a verb, not a pronoun, so it fails to match the first part of my explanation which says that -'e' is only required when "using a pronoun as if it were the verb "to be"".