Pluvia gravis cadit, itaque mater ad forum ire non potest.

Because gravis is an adjective, and it describes the noun pluvia (rain). Latin uses an adjective here just as English does in heavy rain.

• pluvia = rain
• gravis = heavy, serious, weighty

So pluvia gravis means heavy rain.

Graviter is an adverb, meaning heavily or seriously, and would describe a verb, not a noun.

Because it has to agree with pluvia in gender, number, and case.

Here:

• pluvia is feminine
• singular
• nominative, because it is the subject of cadit

So the adjective must match it:

• pluvia gravis = heavy rain

Gravis is a third-declension adjective, and its nominative singular masculine/feminine form is gravis.

Latin often uses cadere (to fall) for things like rain. So pluvia cadit literally means rain falls, which is a normal Latin way to say it is raining or rain is falling.

Here:

• cadit = falls
• it is third person singular present active

Since pluvia is singular, the verb is singular too.

Latin usually does not need a separate subject pronoun unless it is being emphasized.

The ending of the verb already tells you the person and number:

• cadit = he/she/it falls

Since pluvia is already present as the subject, Latin does not need an extra it.

This is very normal in Latin. Subject pronouns are often omitted unless needed for contrast or emphasis.

Itaque means and so, therefore, or so. It introduces the result of what came before.

So the sentence structure is:

• Pluvia gravis cadit = heavy rain is falling
• itaque = therefore / so
• mater ad forum ire non potest = mother cannot go to the forum

It connects the two ideas logically: the rain is the reason she cannot go.

Because mater is the subject of potest.

In this part of the sentence:

• mater = mother
• potest = is able / can

So mater is in the nominative case, which is the case used for the subject of a verb.

If it were matrem, that would be accusative, and it would usually mean she was the direct object of some verb instead.

Because ad means to or toward, and it takes the accusative case.

So:

• ad = to, toward
• forum = accusative singular of forum

Together, ad forum means to the forum.

This is a very common Latin pattern:

• ad + accusative = motion toward a place

Because it follows the preposition ad, and ad requires the accusative.

That is true even though in English forum may look like the object of go. In Latin, the important thing is that the preposition determines the case:

• ad forum = to the forum

Also, forum is a second-declension neuter noun, so its nominative and accusative singular forms are both forum. That is why the form looks the same.

Because possum (I am able, I can) is commonly followed by an infinitive in Latin.

Here:

• potest = is able / can
• ire = to go

So mater ad forum ire non potest literally means mother is not able to go to the forum, or more naturally, mother cannot go to the forum.

This is the normal construction:

• possum + infinitive

Examples:

• currere potest = he/she can run
• venire possumus = we can come

Because non usually negates the word or idea that follows it. Here it negates potest:

• non potest = cannot / is not able

So the sentence says that mother is not able to go.

Latin word order is flexible, but non is very commonly placed right before the verb it negates.

Latin word order is much freer than English word order because Latin uses case endings to show how words function in the sentence.

English depends heavily on position:

• Mother goes to the forum

Latin can move words around more easily because endings show what each word is doing.

In this sentence:

• pluvia is the subject because of its form and function
• mater is the subject of potest
• forum is accusative after ad
• ire is the infinitive with potest

So even if the order changed, the meaning would still usually be clear.

The given order is perfectly natural and emphasizes the flow:

1. heavy rain is falling
2. therefore
3. mother cannot go to the forum

Ire is the present active infinitive of eo, which means to go.

Its basic principal parts are:

• eo
• ire
• ii or ivi
• itum

So here ire means to go.

It is irregular, so learners often notice that it does not look like a typical first-, second-, or third-conjugation infinitive built from a more familiar stem.

Not exactly. In Latin, forum usually means a marketplace, public square, or civic center of a town.

So in this sentence, ad forum ire means going to the public market area or town center, not going to an online discussion forum or a formal debate setting.

English forum comes from the Latin word, but its meaning has broadened and changed over time.