Metto la borraccia accanto agli scarponi da trekking.

Metto is the first-person singular present tense of mettere, which means to put, to place, or sometimes to set.

So:

• mettere = to put
• metto = I put / I’m putting

In this sentence, metto means I put or I’m putting.

A few related forms:

• metti = you put
• mette = he/she puts
• mettiamo = we put
• mettono = they put

In Italian, the subject pronoun is often left out because the verb ending already shows who is doing the action.

Here, metto clearly means I put, so io is not necessary.

• Metto la borraccia... = I put the water bottle...
• Io metto la borraccia... = also correct, but more emphatic

You might include io if you want contrast or emphasis, for example:

• Io metto la borraccia, tu prendi gli scarponi.
  I’ll put the water bottle down, you take the boots.

So omitting io is very normal.

Borraccia usually means a water bottle, especially a reusable bottle, sports bottle, or canteen.

It is not usually just any bottle in a generic sense. It often suggests something practical for carrying water while walking, exercising, cycling, hiking, and so on.

Compare:

• bottiglia = bottle in general
• borraccia = water bottle / flask / canteen

So in this sentence, la borraccia is most naturally the water bottle.

Italian uses articles much more often than English.

So where English might say:

• I put my water bottle next to the hiking boots

Italian often prefers:

• Metto la borraccia accanto agli scarponi da trekking.

Even when English might omit the, Italian often keeps the article.

Here:

• la borraccia = the water bottle

This does not necessarily mean a very specific bottle in a heavily emphasized way; it is just normal Italian usage.

Accanto means next to, beside, or alongside.

It is commonly used with a:

• accanto a = next to / beside

So:

• accanto agli scarponi = next to the boots

You can think of accanto a as a set expression.

Examples:

• Sono accanto alla porta. = I’m next to the door.
• Il gatto dorme accanto al letto. = The cat sleeps next to the bed.

Agli is the combination of:

• a
  • gli = agli

Since the expression is accanto a, and the noun needs the plural article gli, they combine:

• accanto a + gli scarponi → accanto agli scarponi

This is called a contracted preposition.

Very common Italian combinations are:

• a + il = al
• a + lo = allo
• a + la = alla
• a + i = ai
• a + gli = agli
• a + le = alle

So agli is completely normal here.

Because scarponi comes from scarpone, and scarpone begins with sc- followed by a consonant sound.

For masculine plural nouns, Italian uses:

• i with many ordinary masculine plurals
• gli with nouns that in the singular would take lo

Words that take lo/gli often begin with:

• s + consonant: lo studente / gli studenti
• z: lo zaino / gli zaini
• ps: lo psicologo / gli psicologi
• gn: lo gnomo / gli gnomi
• sc before certain consonant sounds, as in scarpone

So:

• singular: lo scarpone
• plural: gli scarponi

Then after a, you get:

• agli scarponi

The singular is scarpone.

• scarpone = boot, especially a heavy boot
• scarponi = boots

In this sentence, scarponi strongly suggests hiking boots or trekking boots, especially because of da trekking.

So:

• lo scarpone = the boot
• gli scarponi = the boots

This is a normal singular/plural change:

• -one → -oni

Da trekking means for trekking or, more naturally in English, hiking / trekking as a type.

So:

• scarponi da trekking = hiking boots / trekking boots

The preposition da is often used in Italian to show purpose, function, or intended use.

Examples:

• scarpe da tennis = tennis shoes
• occhiali da sole = sunglasses
• spazzolino da denti = toothbrush
• scarponi da trekking = hiking boots

So da trekking describes what kind of boots they are.

It is a borrowed word from English, but it is very common in Italian.

Italian often uses trekking in outdoor contexts, especially in phrases like:

• scarponi da trekking
• zaino da trekking
• pantaloni da trekking

A native speaker would find this very natural.

Yes. The Italian present tense often covers both ideas, depending on context.

So Metto la borraccia accanto agli scarponi da trekking could mean:

• I put the water bottle next to the hiking boots
• I’m putting the water bottle next to the hiking boots

Italian does not always separate simple present and present continuous the way English does.

If you really want to stress the ongoing action, Italian can also use:

• Sto mettendo la borraccia accanto agli scarponi da trekking.
  = I’m putting the water bottle next to the hiking boots.

But the simple present metto is very common and natural.

The given order is very natural:

• Metto la borraccia accanto agli scarponi da trekking.

It follows a common pattern:

• verb + object + place expression

You could change the order in some contexts, but it may sound more marked or emphasize something different.

For example:

• Accanto agli scarponi da trekking metto la borraccia.

This puts more focus on where you put it.

So the original sentence is the most neutral and natural version.

Then you would use the singular:

• Metto la borraccia accanto allo scarpone da trekking.

Why allo?

Because:

• a + lo = allo

And the singular is:

• lo scarpone

So:

• singular: accanto allo scarpone
• plural: accanto agli scarponi