I ja ponekad pristajem prebrzo, pa se kasnije predomislim i poželim drugi plan.

Here i means also / too, not just and.

So I ja means:

• I too
• me too
• I also

It usually connects to something said before. For example, if someone else said they also agree too quickly, this speaker is adding: I ja...

If you removed i, then Ja ponekad... would simply mean I sometimes..., without the idea of too.

Yes. Croatian often drops subject pronouns because the verb ending already tells you the person.

• pristajem = I agree / I accept
• predomislim = I change my mind
• poželim = I start wanting / wish for

So ja is not grammatically necessary. It is included for emphasis, contrast, or clarity. In I ja, it is especially natural, because the speaker is stressing I too.

Ponekad means sometimes / occasionally.

Its position is fairly flexible. For example:

• I ja ponekad pristajem prebrzo.
• Ponekad i ja pristajem prebrzo.
• Ja ponekad pristajem prebrzo.

All of these are possible, with slightly different emphasis. In your sentence, ponekad sits in a very natural middle position.

Pristajem is 1st person singular present tense: I agree / I accept / I consent.

It comes from the imperfective verb pristajati. That fits well with ponekad, because the sentence is talking about something that happens from time to time, not one single completed event.

So:

• pristajem = I am in the habit of agreeing / I sometimes agree
• compare perfective pristanem, which more often points to a single completed act of agreeing

Often, yes.

A very common pattern is:

• pristati / pristajati na nešto = to agree to something

For example:

• Pristajem na prijedlog. = I agree to the proposal.

In your sentence, the thing being agreed to is not stated. It is understood from context. English does the same thing:

• I agree too quickly

without always saying exactly what you agree to.

Because prebrzo is a single adverb meaning too quickly / too fast.

It is built from:

• brzo = quickly / fast
• prefix pre- = too, excessively

So:

• brzo = quickly
• prebrzo = too quickly

You could also say previše brzo, which also means too quickly, but prebrzo is shorter and very natural here.

Here pa works like a connector meaning something like:

• so
• and then
• which leads to

In this sentence, it links the first action to what happens afterward:

• I agree too quickly, so/and then later I change my mind...

It is very common in everyday Croatian and often sounds more natural and flowing than a more formal connector.

Because predomisliti se is a reflexive verb, and se is a clitic. In Croatian, clitics usually go very early in the clause, typically in second position.

So the natural order is:

• pa se kasnije predomislim

not:

• pa predomislim se

Even though the dictionary form is predomisliti se, in a sentence the se usually moves forward according to Croatian clitic placement rules.

Predomisliti se means to change one's mind.

The se here is part of the verb. It is not something you translate word-for-word as myself. Learners often want to analyze it literally, but the best approach is to learn it as a whole unit:

• predomisliti se = to change one's mind

In your sentence:

• pa se kasnije predomislim = and then later I change my mind

Because the whole sentence describes a habitual pattern: something that happens sometimes.

So even though the actions happen in sequence, Croatian uses the present tense to describe what typically happens:

• I sometimes agree too quickly
• then later I change my mind
• and want another plan

This is very similar to English, which also uses the present for habits.

Because Croatian can use perfective present forms to describe repeated whole events, especially when the speaker is talking about what tends to happen on particular occasions.

That gives a slightly event-like feeling:

• predomislim = I end up changing my mind
• poželim = I end up wanting / I suddenly want

This is different from using more ongoing or state-like forms such as:

• predomišljam se = I am wavering / I keep reconsidering
• želim = I want

So the sentence is not focusing on a continuous state, but on what happens as a complete turn of events.

Not exactly.

• želim = I want
• poželim = I suddenly want / I come to want / I feel a wish for

So poželim often sounds a bit more like the desire appears at that moment.

In this sentence, that fits the sequence well:

1. I agree too quickly.
2. Later I change my mind.
3. Then I start wanting another plan.

So poželim is more event-like than želim.

It can mean both, depending on context.

Here drugi plan most naturally means:

• another plan
• a different plan
• an alternative plan

It does not necessarily mean literally plan number two. In everyday Croatian, drugi very often means another.

If you wanted to stress different in character, you might say drugačiji plan, but drugi plan is very natural here.

It is the accusative singular, because it is the direct object of poželim.

• poželim što? → drugi plan

Since plan is a masculine inanimate noun, its accusative singular looks the same as its nominative singular:

• nominative: drugi plan
• accusative: drugi plan

So the form does not change, even though the case function does.