Baculum tamen leve est, et avus dicit se eo facile uti posse.

Because baculum is neuter singular nominative, and the adjective has to agree with it.

The adjective levis, leve means light:

• masculine/feminine nominative singular: levis
• neuter nominative singular: leve

So:

• baculum leve est = the stick is light

A native English speaker often expects something like levum, but this adjective is third declension, not first/second declension, so its neuter nominative singular is leve.

Tamen usually means however, nevertheless, or still.

So Baculum tamen leve est means something like:

• The stick, however, is light
• The stick is light, though
• Nevertheless, the stick is light

It signals some contrast with what came before. Latin often places tamen near the beginning of the clause, frequently after the first word, as it does here.

Because Latin is using indirect statement after dicit (he says).

A very common Latin pattern is:

• verb of saying/thinking/perceiving
  • accusative subject
    • infinitive

So:

• avus dicit se ... posse

literally means:

• grandfather says himself to be able ...

In smoother English:

• grandfather says that he can ...

Here se is the accusative subject of the infinitive phrase.

Because se is reflexive: it refers back to the subject of the main clause, here avus.

So:

• avus dicit se ... posse = the grandfather says that he himself can ...

If Latin wanted to say that the grandfather says someone else can do it, it would use a non-reflexive form such as eum.

This is an important distinction:

• se = himself/herself/themselves, referring back to the subject
• eum / eam / eos / eas = him/her/them, someone else

Eo is ablative singular of is, ea, id (he, she, it / this, that), and here it refers to baculum.

It is ablative because the verb utor, uti (to use) takes the ablative case.

So:

• eo uti = to use it
• literally, something like to make use of it

That is one of the most important things to remember with utor:

• it does not take a direct object in the accusative
• it takes an ablative

Because utor, uti, usus sum is a deponent verb.

A deponent verb:

• has passive forms
• but an active meaning

So even though uti looks like a passive infinitive to an English-speaking learner, it actually means:

• to use

This is perfectly normal for deponent verbs in Latin.

Other common deponent verbs work the same way, but utor is especially worth memorizing because it is common and it takes the ablative.

It is an indirect statement.

You can break it down like this:

• avus dicit = the grandfather says
• se = that he
• eo uti = use it
• posse = can / to be able to

Very literally:

• the grandfather says himself to be able to use it easily

Natural English:

• the grandfather says that he can use it easily

So the structure is:

• main verb: dicit
• accusative subject of the indirect statement: se
• infinitives: uti and posse

Here posse governs uti:

• uti posse = to be able to use

Because after dicit, Latin is not using a normal finite clause like English often does. Instead, it uses indirect statement with an infinitive.

So Latin says:

• dicit se ... posse

rather than:

• dicit quod ... potest

The infinitive posse is therefore exactly what we expect.

Compare:

• potest = he is able / he can
  a normal finite verb

• posse = to be able
  the infinitive, used in indirect statement here

Yes. Facile here is an adverb, meaning easily.

It modifies the verbal idea:

• eo facile uti posse = to be able to use it easily

A learner might expect faciliter, since many Latin adverbs end in -ter, and faciliter does exist. But facile is also a standard and very common adverb form from facilis.

So here:

• facile = easily

Not really. It is very normal Latin word order.

A few points:

• Baculum tamen leve est
  Latin often puts tamen near the beginning, often after the first word.

• avus dicit se eo facile uti posse
  Latin often puts the main verb first or early, then the infinitive phrase after it.

• posse at the end
  Final position for an infinitive or important verbal element is very common.

Also, Latin word order is much freer than English word order because case endings show grammatical relationships. So the sentence may feel unusual from an English perspective, but it is quite natural in Latin.