Civis incensus respondet, quasi immunis sit.

Latin has no articles, so civis can mean a citizen, the citizen, or just citizen depending on context.

In this sentence, civis is nominative singular, so it is the subject of the verb. English has to choose an article, but Latin does not.

Civis is nominative singular.

That tells you it is the subject of respondet. Its basic dictionary form is civis, civis and it means citizen.

Because civis is a 3rd-declension noun, its nominative singular does not end in -us or -a, which can feel less familiar to beginners.

Incensus is an adjective, originally also the perfect passive participle of incendo in some contexts, but here it works as an adjective meaning something like angry, enraged, or inflamed.

It agrees with civis in case, number, and gender:

• nominative
• singular
• masculine

So civis incensus means the angry/enraged citizen.

Because it agrees with civis.

In this sentence, incensus is masculine nominative singular. That suggests the citizen is understood as masculine. If the citizen were feminine, you would expect incensa.

So the form of the adjective gives you gender information that civis by itself does not make explicit.

Respondet is:

• 3rd person
• singular
• present
• active
• indicative

It comes from respondeo, respondere, meaning to answer or to reply.

So civis incensus respondet means the angry citizen replies/is replying.

Because respondet is present indicative. Latin often uses the present just as English does for a simple statement about what someone is doing.

Depending on context, it could be translated as:

• replies
• is replying
• answers

Latin present tense is often slightly more flexible than a single English form.

Quasi means as if, as though, or sometimes just as if.

It introduces a comparison that is not being presented as a fact, but as an appearance or attitude. So the citizen replies as if he were something.

That sets up the next clause: quasi immunis sit.

Because after quasi meaning as if, Latin commonly uses the subjunctive.

So:

• est = he is (indicative, straightforward statement of fact)
• sit = he may be / he is in the subjunctive, here used because the clause expresses something imagined, supposed, or only apparent

In other words, the sentence does not say he really is immunis. It says he answers as if he were.

Sit is the present subjunctive, 3rd person singular, of sum, esse (to be).

So it means he/she/it may be, but in this kind of clause the best English translation is usually just were or is, depending on style:

• as if he were exempt
• as if he is exempt is less natural in standard English

Immunis is nominative singular.

It is a predicate adjective with the implied subject of sit. That implied subject is the same person as civis.

So the structure is basically:

• civis ... respondet
• quasi [civis] immunis sit

In English: The angry citizen replies as if he were exempt.

Because it describes the subject, immunis stays in the nominative.

It is related, but the meaning in Latin is often broader.

Immunis can mean:

• exempt
• free from a burden
• not subject to a duty, tax, or obligation
• sometimes more generally protected from something

So in many contexts it does not mean specifically medically immune. Here, depending on the meaning already given to the learner, it probably means something like exempt or not subject to the usual obligation.

It is understood.

Latin often leaves out a subject pronoun when the verb ending already shows the person and number. Here sit is 3rd person singular, and the natural understood subject is the same as the main subject, civis.

So Latin does not need to say is or repeat civis.

Latin word order is more flexible than English because the endings show grammatical relationships.

This order is quite natural:

• Civis incensus introduces the subject with its description
• respondet gives the main action
• quasi immunis sit adds the comparison

The sentence could be rearranged in other ways without changing the basic meaning, but this order is clear and stylistically straightforward.

The comma helps separate the main clause from the quasi clause:

• Civis incensus respondet
• quasi immunis sit

In modern printed Latin, punctuation is editorial and not part of the ancient language in the same strict way as endings and forms are. So the comma is useful for reading, but the grammar does not depend on it.

Very literal would be:

An angry citizen replies, as if he were exempt.

Or even more word-for-word:

The enraged citizen responds, as if he may be exempt.

But better English usually uses were after as if, because the idea is not presented as true fact.

So the most natural translation is something like:

The angry citizen replies as if he were exempt.