Ictus gladii scutum frangit.

The subject is ictus.

A good beginner way to see it is:

• ictus = the thing doing the action
• scutum = the thing receiving the action
• frangit = the action itself

So ictus is the nominative subject of the verb frangit.

Gladii is in the genitive singular. The genitive often corresponds to English of.

So ictus gladii means something like:

• the blow of the sword
• a sword’s blow
• the strike of the sword

Latin does not need a separate word for of here, because the ending -i on gladii already shows that relationship.

Yes, in isolation gladii could also be nominative plural of gladius.

But in this sentence, that does not fit well. Here is why:

• frangit is singular, so it wants a singular subject
• ictus works naturally as that singular subject
• gladii fits very naturally as a genitive dependent on ictus

So in context, gladii is understood as genitive singular, not nominative plural.

Because it is the thing being broken by frangit.

The verb frango, frangere is transitive, so it can take a direct object. In this sentence, scutum is that object.

One small complication is that scutum is a neuter noun, and in many neuter nouns the nominative and accusative singular look the same. So the form by itself could be either nominative or accusative.

But the sentence structure makes it clear:

• ictus is already the subject
• scutum is therefore understood as the accusative direct object

Frangit is:

• present tense
• active voice
• indicative mood
• third person singular

So it means he/she/it breaks or is breaking, depending on context.

Because it is third person singular, it matches a singular subject — here, ictus.

Classical Latin has no articles like English the or a/an.

So:

• ictus can mean a blow or the blow
• gladii can mean of a sword or of the sword
• scutum can mean a shield or the shield

Which one sounds best depends on context. Latin usually leaves that to the reader or listener to infer.

The word order matters much less in Latin than in English, because the endings show each word’s job.

Here:

• ictus = subject
• gladii = dependent genitive
• scutum = direct object
• frangit = verb

Latin often places the verb at the end, as in this sentence, but that is a tendency rather than a strict rule.

A different order could still mean the same basic thing, though the emphasis might change. For example, moving scutum earlier could make the shield more prominent.

Ictus is a fourth-declension masculine noun, not a second-declension one.

That is why its nominative singular ends in -us, but its genitive is not -i. Its principal forms are like this:

• nominative singular: ictus
• genitive singular: ictūs

So even though ictus looks a bit like a second-declension noun at first glance, it belongs to a different declension pattern.

This is a very common thing for beginners to notice: the ending -us does not always mean second declension.

Yes, but only grammatically.

Scutum is neuter. That does not mean the shield is somehow biologically neutral in the way English speakers might think of gender. In Latin, grammatical gender is mainly a noun class.

What matters is that any adjectives or pronouns referring to scutum would need to agree with its neuter gender.

So its gender matters for grammar, not for real-world sex or animacy.

Because the verb ending already tells you the person and number.

The ending -it in frangit means third person singular. Latin can therefore leave out a separate pronoun such as it.

In this sentence, Latin goes further and explicitly names the subject as ictus, so there is no need for any extra subject pronoun at all.