Avus meminit grandinem olim tam gravem cecidisse ut vitis paene frangeretur.

Meminit is one of those Latin verbs whose perfect form has a present meaning. The basic verb is memini, and it means I remember.

So:

• meminit = he/she remembers
• not he/she remembered

This is a very common thing for learners to notice, because the form looks like a perfect tense, but the meaning is present.

Because after meminit, Latin often uses an indirect statement construction, also called accusative + infinitive.

In that construction:

• the subject of the remembered statement goes into the accusative
• the verb of the remembered statement goes into the infinitive

So in grandinem ... cecidisse:

• grandinem = accusative subject of the infinitive
• cecidisse = infinitive verb

Even though grando is the thing doing the falling, it still appears in the accusative because it is the subject inside indirect statement.

For the same reason: this is indirect statement after meminit.

Latin says, literally, something like:

• Grandfather remembers hail to have fallen...

That sounds unnatural in English, so we translate it more naturally as:

• Grandfather remembers that hail once fell...

So:

• cecidit would be a normal finite verb: it fell
• cec idisse is the perfect infinitive: to have fallen

After meminit, Latin prefers the infinitive construction here.

It helps to break it up like this:

• grandinem = hail, accusative, subject of the infinitive
• olim = once, long ago
• tam gravem = so heavy
• cec idisse = to have fallen

So the idea is:

• that hail once fell so heavily
• or more literally, that hail once fell so heavy

The adjective gravem agrees with grandinem, not with the verb.

Tam ... ut is a very common Latin pattern meaning so ... that.

Here:

• tam gravem = so heavy
• ut vitis paene frangeretur = that the vine was almost broken

So the sentence expresses a result:

• the hail was so heavy
• that something happened as a result

This is called a result clause.

Latin is describing the hail itself as heavy, not directly describing the manner of falling.

So:

• tam gravem grandinem = hail so heavy
• not fell heavily in a strictly grammatical sense

English often prefers to say something like hail fell so heavily, but Latin is using the adjective with the noun:

• grandinem ... gravem = heavy hail

Both languages are expressing nearly the same idea, but they package it differently.

Because it is inside a result clause introduced by ut.

In Latin, result clauses normally take the subjunctive:

• tam ... ut ...
• so ... that ...

So frangeretur is subjunctive because it belongs to that clause of result.

Because the result belongs to a past situation.

The remembered event is that hail fell long ago, and the near-breaking of the vine belongs to that same past scene. Latin therefore uses the imperfect subjunctive in the result clause:

• frangeretur = was being broken / was broken / would be broken in context
• here, most naturally, was almost broken

So the imperfect subjunctive fits a past result.

Because the vine is receiving the action, not doing it.

The active verb is frango = I break.
Its passive is frangor = I am broken.

So:

• frangeretur = was being broken or, in smoother English here, was broken
• with paene, it becomes was almost broken

The vine is not breaking something else; the hail is almost breaking the vine.

Because vitis is the subject of frangeretur.

The ut clause is its own clause, with its own subject and verb:

• vitis = subject
• frangeretur = verb

So vitis is nominative because it is the thing that was almost broken.

Olim can mean things like:

• once
• formerly
• long ago

In this sentence, it points to a time in the past, so once or long ago fits well.

It tells us that this was not a recent event, but something the grandfather remembers from earlier times.

Paene means almost.

So:

• frangeretur = was broken / was being broken
• paene frangeretur = was almost broken

It softens the result: the vine did not necessarily break completely, but it came very close.

Because Latin has no definite or indefinite articles.

So Latin does not have separate words for:

• the
• a
• an

Whether we translate avus as grandfather, the grandfather, or a grandfather depends on context. The same is true for vitis.

In a normal English translation of this sentence, Grandfather or the grandfather and the vine may be supplied naturally, but Latin itself does not state the article.