Si grando in pomarium ceciderit, colona multum damni patietur.

In this sentence, si ... ceciderit ... patietur is a standard future more vivid condition in Latin:

• si grando ... ceciderit = if the hail has fallen / if the hail falls
• colona ... patietur = the farmer will suffer

Latin often uses the future perfect in the if-clause when English would usually just use a present tense:

• Latin: Si hoc feceris, gaudebo.
• English: If you do this, I will be glad.

So ceciderit is not strange here; it is the normal Latin way to say if the hail falls with future reference.

No. Although ceciderit can look like either:

• future perfect indicative, or
• perfect subjunctive

here it is understood as future perfect indicative because of the conditional pattern:

• si
  • future perfect
• main clause in the future

So:

• Si grando in pomarium ceciderit, colona multum damni patietur.
• If hail falls into the orchard, the farmer will suffer much damage.

This is an indicative condition, not a subjunctive one.

Because patior, pati, passus sum is a deponent verb.

A deponent verb:

• has passive forms
• but an active meaning

So patietur looks passive in form, but it means:

• he/she will suffer
• not he/she will be suffered

This is something English speakers often need to get used to in Latin.

Grando is nominative singular. It is the subject of ceciderit.

So the structure is:

• grando = the hail
• ceciderit = will have fallen / falls

Latin does not rely as heavily on word order as English does, so you identify the subject mainly by case and verb agreement, not just by position in the sentence.

Because in takes different cases depending on meaning:

• in + accusative = into, onto (motion toward)
• in + ablative = in, on (location)

Here the hail is falling into the orchard, so Latin uses the accusative:

• in pomarium = into the orchard

If it meant in the orchard as a location, it would be:

• in pomario

Pomarium is a noun meaning orchard or fruit-garden.

In this sentence it is:

• accusative singular
• because it follows in with a sense of motion: into the orchard

So:

• in pomarium = into the orchard

Multum damni is a very common Latin way to say much damage.

It uses:

• multum = much, functioning as a neuter singular quantity word
• damni = of damage, a partitive genitive

Literally, it is something like:

• much of damage

This is idiomatic Latin.

By contrast, multa damna would mean something more like:

• many damages / many losses

That is grammatically possible in some contexts, but it is not the usual way to express the general idea much damage here.

Damni is genitive singular from damnum.

It depends on multum in a partitive genitive construction. Latin often uses the genitive after words of quantity:

• multum temporis = much time
• satis pecuniae = enough money
• nihil dubii = nothing of doubt / no doubt

So here:

• multum damni = much damage

Yes. The whole phrase multum damni functions as the thing suffered, so it is the object in sense.

Inside that phrase:

• multum is the main accusative quantity word
• damni is genitive, depending on multum

So although damni itself is not accusative, the phrase as a whole works as the object of patietur.

Latin grando is often used in the singular to mean hail as a weather phenomenon, much as English can say hail without making it plural.

So the singular here is perfectly natural:

• grando = hail

It does not have to mean just one single hailstone.

Yes. Latin word order is fairly flexible because the endings show the grammatical roles.

This sentence is arranged as:

• Si grando in pomarium ceciderit, colona multum damni patietur.

That is a very natural order:

1. the if-clause
2. then the main clause

But Latin could rearrange parts for emphasis, for example:

• Si in pomarium grando ceciderit, multum damni colona patietur.

The meaning would stay basically the same, though the emphasis might shift slightly.

As written, colona is nominative singular feminine.

So it means:

• the woman farmer
• or the female settler/colonist, depending on context

A learner might be more familiar with colonus for farmer/settler. If the sentence is referring specifically to a woman, colona makes that feminine.

They are:

• si = if
• grando, grandinis (f.) = hail
• in = in, into
• pomarium, pomarii (n.) = orchard
• cado, cadere, cecidi = fall
• colona, colonae (f.) = female farmer / female settler
• multus, multa, multum = much, many
• damnum, damni (n.) = damage, loss
• patior, pati, passus sum = suffer, endure

Knowing the dictionary form helps explain why the actual forms look the way they do in the sentence.