I am using the Collar and Daniell, Beginner's Latin Book to learn latin on my own and need a bit of help to translate the sentence Novum equum laudat (Exercise 48.I.11., p 15). I know that laudat is praise in the present indicative tense, third person singular (i.e. praises), and that equum is the accusative singular of horse (equus) (i.e. horse is the direct object). Since adjectives take the ending of the noun they modify, would this sentence translate as "He praises the new horse."? If so, why.
You are correct. Doubly so, in fact, as your grammatical analysis is spot on.
Note that technically it could also be "She praises" or even "It praises" depending on the subject, which would have been established in previous sentences. In Latin, you don't need an explicit subject if it's already been established.