The Aeneid is poetry: the rhythm of the words is part of the art form. But Latin poetry works on different principles from English poetry, in that it is based on syllable quantity: the Aeneid is built on a pattern of long and short syllables.

The gerund is a noun formed from a verb. In English gerunds are formed by adding ‘-ing’ to the stem of a verb; this makes them look like present participles. Nevertheless a gerund functions very differently from a participle, so it is important to be able to distinguish the two.

The perfect forms of deponent verbs, like those of regular verbs, are formed from the third principal part. But in the case of deponent verbs these are periphrastic; that is, each verb form is made up of two separate words, a participle and a form of sum, as in vēnātus sum from vēnor. Conjugating periphrastic verbs in Latin is trickier than conjugating one-word verbs, because both parts inflect. The form of sum is conjugated as usual, while the participle changes as necessary to agree with the subject in gender and number.

Inflection

The key element of every sentence, both in English and in Latin, is a verb: a word indicating the action described by the sentence (e.g. ‘go’, ‘is’, ‘learn’, ‘eat’). English verbs can be identified by the way they inflect (change shape): a word to which ‘-ed’ and ‘-ing’ can be added is a verb. Thus ‘learn’ can be identified as a verb because of the forms ‘learned’ and ‘learning’. Likewise, if you put a verb after ‘they’ and then replace the ‘they’ by ‘he’, you will usually find that the verb then gets an ‘-s’ at the end. Thus ‘they eat’ → ‘he eats’, ‘they learn’ → ‘he learns’, etc. Some common verbs inflect in other ways, but they still indicate that they are verbs by the fact that they have different forms for past and present and for use after ‘they’ and after ‘he’: ‘run’ and ‘sit’ become ‘ran’ and ‘sat’ in the past, and ‘they are’ becomes ‘he is’. A problem, however, is that some English verbs are periphrastic (formed of two or more separate words): ‘is running’, ‘had run’, ‘did run’, ‘will be running’, and ‘will have been running’ are all periphrastic verb forms and each express one single idea – and each would be expressed with just one word in Latin. It is important to be able to spot English verbs, and to be able to identify periphrastic verb forms as units, in order to deal successfully with Latin. Those who are uncertain of their abilities in this area would benefit from doing the exercises on these points in chapter 63.1–2.

Verbs normally have subjects, that is, a word for the person or thing that does the action expressed by the verb (in the examples above, ‘he’ and ‘they’ are the subjects).

The last case is the ablative. In the declensions we have so far seen, the ablative endings are the same as those of the dative except in the singular of the first declension and in the feminine singular of adjectives: in those forms it ends in a long -ā. The length of the -ā is important because it serves to distinguish the ablative from the nominative. With the ablative added, the paradigms we have seen can be completed; words ending in -r and in -ius have the same ablative forms as other second-declension words, so the paradigms seen in chapter 8 pose no additional difficulties.