Verbs: present tenses

Why not to write est audit

Sometimes, when translating sentences into Latin, people are tempted to write something like this:

He is listening.
*est audit.

The word est makes that Latin sentence ungrammatical: He is listening should be translated into Latin as the single word audit.

He is listening.
audit.

English

In English and Latin, verbs change their form to indicate tense, the time of the action of the verb. Each verb consists of one word.

In these sentences, the verbs are in the present tense.

English verbs have other ways of indicating the present tense:

In those sentences, each verb consisted of two words: an auxiliary verb (is, are, does) and another verb form (entering, running, praise). Verbs consisting of two or more words are sometimes called compound verbs.

Latin

Latin verbs have only one way of indicating the present tense: with a one-word present tense form:

Scintilla is entering the house.
Scintilla casam intrat.
Quintus and Horatia are running into the field.
Quintus et Horatia in agrum currunt.
Flaccus does praise his son.
Flaccus filium laudat.

Latin does not have any present tense compound verbs.