Danas mogu da idem u park.

Mogu da idem literally means I can that I go, but in natural English it simply means I can go.

This is a very common Serbian pattern:

• mogu = I can
• da idem = to go / that I go

After modal verbs like moći (can, be able to), Serbian often uses da + present tense instead of an infinitive.

So:

• Mogu da idem = I can go
• Mogu da radim = I can work
• Mogu da spavam = I can sleep

You may also sometimes see an infinitive in Serbian, but da + present is extremely common and very natural.

Because idem is the 1st person singular present tense form of ići (to go).

The subject here is understood to be I, so the verb must match that:

• ja idem = I go / I am going
• ti ideš = you go
• on/ona/ono ide = he/she/it goes

Since mogu already means I can, the second verb also stays in the I form:

• mogu da idem = I can go

Serbian often leaves out subject pronouns when they are already clear from the verb form.

In this sentence:

• mogu already tells you the subject is I
• idem also agrees with I

So ja is not necessary.

You could say:

• Danas ja mogu da idem u park.

But that usually adds emphasis, something like:

• Today I can go to the park
  or
• As for me, today I can go to the park

The neutral version is simply:

• Danas mogu da idem u park.

Danas means today.

It is an adverb of time, and Serbian word order is fairly flexible. Putting danas first is very natural because it sets the time frame right away:

• Danas mogu da idem u park. = Today I can go to the park.

You could also hear:

• Mogu danas da idem u park.
• Mogu da idem danas u park.

These are all possible, but they can sound slightly different in emphasis. The version with danas first is a very normal, neutral way to say it.

Because after u with motion toward a place, Serbian uses the accusative case.

Here the idea is going into/to the park, so it is movement toward a destination:

• u park = to the park

Compare:

• Idem u park. = I’m going to the park.
• Ja sam u parku. = I am in the park.

So:

• u park = direction, motion, destination → accusative
• u parku = location, being inside the park → locative

This is a very important Serbian pattern:

• Idem u školu. = I’m going to school.
• Ja sam u školi. = I’m at school.

Because park is a masculine noun, and for many masculine inanimate nouns, the accusative singular looks exactly like the nominative singular.

So:

• park = nominative
• park = accusative

That is why you see:

• u park and not some visibly different form

Compare that with the locative:

• u parku = in the park

So even though the case changes, the form does not always change visibly in the accusative.

It can mean either, depending on context.

Mogu from moći can express:

• ability → I can / I’m able to
• possibility → I can / it’s possible for me to
• sometimes permission → I may / I’m allowed to

So Danas mogu da idem u park could mean:

• Today I can go to the park because I have time
• Today I’m able to go to the park
• Today I’m allowed to go to the park

Without extra context, Serbian leaves this open just like English often does with can.

Ići is the basic imperfective verb meaning to go.

In mogu da idem u park, the focus is simply on the action of going, not on completing the trip as a single whole event.

Serbian often distinguishes between:

• ići = imperfective, ongoing/general/repeated going
• otići = perfective, to leave/go off, one completed departure

So:

• Mogu da idem u park. = I can go to the park.
• Mogu da odem u park. = also possible, but more like I can go off to the park / I can make the trip to the park

In many everyday situations, both may appear, but idem is a very natural general choice for beginners to learn first.

Not by itself. Because of mogu, the sentence includes the idea of can / am able to / may.

So:

• Danas mogu da idem u park. = Today I can go to the park.

If you want Today I am going to the park, you would say something like:

• Danas idem u park.

That means Today I’m going to the park or Today I go to the park, depending on context.

So mogu adds an extra layer of meaning and should not be ignored.

In some contexts, yes, but mogu da idem is the more common and more natural everyday pattern for many speakers.

Serbian has two ways to express this kind of structure:

• mogu da idem
• mogu ići

Both can mean I can go, but da + present tense is extremely frequent in modern Serbian and is usually the safest pattern for learners.

So if you are unsure, use:

• mogu da idem

The sentence breaks down like this:

• Danas = today
• mogu = I can
• da idem = to go
• u park = to the park

So the structure is roughly:

time + modal verb + da + present verb + destination

A similar example:

• Sutra mogu da idem u školu. = Tomorrow I can go to school.
• Večeras mogu da radim. = Tonight I can work.

This is a very useful sentence pattern to remember.