Vidim krpelja na šapi.

Vidim means I see.

It is the:

• 1st person singular
• present tense
• of the verb videti / vidjeti (to see)

So vidim by itself already tells you the subject is I.

In Serbian, subject pronouns are often omitted because the verb ending already shows who is doing the action.

So:

• Vidim = I see
• Ja vidim = I see, with extra emphasis on I

You would add ja only if you want contrast or emphasis, for example:

• Ja vidim krpelja, a ti ne. = I see the tick, but you don’t.

Because krpelja is in the accusative singular.

The verb videti (to see) takes a direct object, and direct objects normally go in the accusative.

The dictionary form is:

• krpelj = tick

But in this sentence it becomes:

• krpelja

That is because krpelj is a masculine animate noun. In Serbian, masculine animate nouns usually have:

• nominative singular: krpelj
• accusative singular: krpelja

In Serbian grammar, animate mainly refers to living beings or things treated grammatically like living beings.

This matters because masculine nouns behave differently in the accusative:

• masculine animate: accusative usually matches the genitive
• masculine inanimate: accusative usually matches the nominative

So:

• Vidim krpelja. = I see a tick.
• but something inanimate would often stay unchanged in the accusative

Even though a tick is tiny, it is still grammatically animate.

Because after na when it means on in the sense of location, Serbian uses the locative case.

The base form is:

• šapa = paw

In the locative singular, it becomes:

• šapi

So:

• na šapi = on the paw

No. Na can take different cases depending on the meaning.

Here is the important contrast:

• na + locative = location
  
  • na šapi = on the paw
• na + accusative = movement onto something
  
  • for example, stavio je krpelja na šapu = he put the tick onto the paw

In your sentence, the tick is already located there, so locative is used.

Yes. Šapa is a feminine noun.

Its basic form ends in -a, which is very common for feminine nouns in Serbian:

• šapa = nominative singular
• šapi = locative singular

So the phrase na šapi follows a very common pattern for feminine nouns after a preposition of location.

It can mean either, depending on context.

Serbian does not have articles like the and a/an, so the sentence itself does not specify that.

So:

• na šapi could be on the paw
• or on a paw

The listener figures it out from context.

Yes, Serbian word order is more flexible than English.

The neutral order here is:

• Vidim krpelja na šapi.

But you could also hear:

• Na šapi vidim krpelja. = emphasizing on the paw
• Krpelja vidim na šapi. = emphasizing the tick

The meaning stays basically the same, but the focus changes.

A helpful rough guide is:

• kr-pel-ya

The important part is lj, which is a single Serbian sound, not a normal English l plus j. It sounds somewhat like the lli in million for many English speakers.

So:

• krpelj ≈ kr-pehly
• krpelja ≈ kr-pehlya

Also:

• š sounds like sh
• so šapi sounds roughly like SHAH-pee

Yes, it is perfectly natural.

It is short, direct, and idiomatic:

• Vidim krpelja na šapi.

A speaker might also say slightly fuller versions depending on context, for example:

• Vidim krpelja na njegovoj šapi. = I see a tick on his paw.
• Na šapi je krpelj. = There is a tick on the paw.

But your original sentence is completely normal.