Bérelhettek kenut, csak hozzátok vissza időben.

Hungarian often leaves subject pronouns out when the verb ending already shows the person and number.

Here:

• bérelhettek = you (plural) can/may rent
• hozzátok = you (plural) bring it back in a command

So adding ti (you all) would usually only be for emphasis.

Bérelhettek comes from:

• bérel = rent
• -het- / -hat- = can / may / be able to
• -tek = you plural

So bérelhettek literally means something like:

• you can rent
• you may rent
• sometimes you could rent, depending on context

In this sentence, it most naturally means you can / may rent.

It is:

• plural
• informal

So the speaker is talking to more than one person in an informal way.

If Hungarian wanted polite/formal you, it would normally use a 3rd-person form instead, not this one.

Because kenut is the accusative form, used for the direct object.

• kenu = canoe
• kenut = canoe as the thing being rented

Hungarian marks direct objects with -t, so:

• Bérelhettek kenut = You can rent a canoe

Hungarian often uses a bare noun where English needs a/an.

So:

• kenut can naturally mean a canoe

If the sentence said egy kenut, that would put a bit more emphasis on one canoe. But without egy, the meaning is still perfectly natural.

This also matters for verb conjugation: because kenut is indefinite here, the verb is in the indefinite conjugation: bérelhettek.

Hozzátok is the 2nd person plural imperative, definite conjugation of hozni (to bring).

So it means:

• bring it back (said to more than one person)

Why definite? Because the thing to be brought back is understood as a specific object: the canoe you rented.

Compare:

• hozzatok = bring (something), indefinite
• hozzátok = bring it / bring them, definite

Because vissza is a verbal prefix, and in a neutral imperative/command, Hungarian usually puts the prefix after the verb.

So:

• visszahozzátok = usually a statement, you bring it back
• hozzátok vissza! = a command, bring it back!

This is a very common Hungarian pattern with prefixed verbs.

Because the object is treated differently in the two clauses.

First clause

• Bérelhettek kenut
• kenut = an indefinite object (a canoe)
• so Hungarian uses the indefinite conjugation: bérelhettek

Second clause

• csak hozzátok vissza időben
• the object is now understood as a specific thing: the canoe you rented
• so Hungarian uses the definite conjugation: hozzátok

This switch is very natural in Hungarian.

Here csak means something like:

• just
• only
• just make sure to

So the sentence has the sense:

• You can rent a canoe, just bring it back on time.

It softens the instruction a little and adds a condition.

Időben literally means in time, and in this sentence the most natural English meaning is:

• on time
• before the deadline
• in good time

So hozzátok vissza időben means bring it back on time.

Yes, the object is omitted because it is already clear from the context.

Hungarian often leaves out words that are obvious. Here, after Bérelhettek kenut, the second clause clearly refers to that canoe, so Hungarian does not need to repeat it.

A fuller version could be:

• Bérelhettek kenut, csak azt hozzátok vissza időben.

But that would sound more emphatic than necessary.