Translate into English: equum lupus celeriter cepit.

As ever, the first step is to find the subject, verb and object of the sentence. The subject is in the nominative case, the object in the accusative case and the verb will agree with the subject in number. In this sentence the ending -m of equum is a strong indication that it is the object of the sentence and the -s of lupus tells us that it is the subject (as both of these words are 2nd declension masculine). Our very is cepit. Since Latin can be in a different word order to English it is important to establish which order you will translate the words. In English we normally follow the order 'subject verb object...' and hence we will translate this sentence in the order 'lupus cepit equum celeriter'. Lupus means wolf and equus means horse. Cepit is the 3rd person singular perfect active indicative form of capio - I capture. Thus the sentence translates 'the wolf captured the horse'. The -iter endind of celeriter tells us that it is adverbial and hence modifies cepit. The final translation of this sentence should be 'the wolf captured the horse quickly'.