Learn Hardcore Croatian: Sve danas dobro razumijem, jer učiteljica objašnjava polako. - Today I understand everything well because the teacher explains slowly.

Sve danas dobro razumijem is the most natural way to say “Today I understand everything well.”
- The new / focused information (what you understand) is at the beginning: Sve.
- Then you add when: danas.
- Then how: dobro.
- The verb razumijem comes last, which is very common in Croatian main clauses.
Razumijem sve danas dobro sounds strange and somewhat “scrambled” to a native speaker. You could say:
- Danas sve dobro razumijem.
- Danas dobro razumijem sve.
In Croatian, word order is flexible, but there is still a “default” order that sounds most natural; here it’s Sve danas dobro razumijem or Danas sve dobro razumijem.

Why is there no ja (“I”) or ona (“she”) in the sentence?

Croatian usually drops subject pronouns (it’s a “pro‑drop” language) because the verb ending already shows the person and number:

razumijem = I understand (1st person singular) → ja is understood.
objašnjava = he/she/it explains (3rd person singular) → here učiteljica is the subject, so there is no need for ona.

You could say:

Ja sve danas dobro razumijem, jer učiteljica objašnjava polako.
… jer ona objašnjava polako.

These are correct, but they sound more emphatic, like “I (not someone else) understand everything today well…” or “because she (not someone else) explains slowly.”

In neutral speech, you normally just omit ja and ona.

What exactly is sve here? Is it “all” or “everything”, and what case is it?

In this sentence:

sve = everything, referring to “all the things” you are learning.
It’s in the accusative singular neuter, functioning as the direct object of razumijem (“I understand what?” → sve).

Some useful patterns:

Vidim sve. – I see everything. (accusative object)
Sve je dobro. – Everything is good. (nominative subject)

The form sve looks the same in nominative and accusative neuter singular; the role is decided by its position and function in the sentence. Here, because it’s the object of razumijem, it’s accusative.

Is dobro an adjective (“good”) or an adverb (“well”) in this sentence?

Here dobro is an adverb, meaning “well”, describing how you understand:

razumijem – I understand
dobro razumijem – I understand well

Compare:

dobar učitelj – a good teacher (adjective, masculine)
dobra učiteljica – a good female teacher (adjective, feminine)
dobro objašnjava – (she) explains well (adverb)

Same form dobro, but:

as an adjective: it agrees with a noun (gender, number, case).
as an adverb: it modifies a verb and doesn’t change its form.

In Sve danas dobro razumijem, it modifies the verb razumijem, so it’s an adverb.

What tense and person is razumijem, and how is it formed?

razumijem is:

Present tense
1st person singular
From the verb razumjeti – “to understand”

Present tense of razumjeti (a bit irregular) is:

(ja) razumijem – I understand
(ti) razumiješ – you understand (sg.)
(on/ona/ono) razumije – he/she/it understands
(mi) razumijemo – we understand
(vi) razumijete – you understand (pl./formal)
(oni/one/ona) razumiju – they understand

So razumijem clearly marks the subject as “I”, which is why ja is not needed.

Why is there a comma before jer? Do you always put a comma before jer?

Yes, in standard Croatian you normally put a comma before jer when it introduces a reason clause:

Sve danas dobro razumijem, jer učiteljica objašnjava polako.
Ne mogu doći, jer moram raditi. – I can’t come because I have to work.

jer behaves like a subordinating conjunction (“because”), and the rule is: main clause, comma, then the “jer” clause.

You can also reverse the order, and then there is no comma before the main clause:

Jer učiteljica objašnjava polako, sve danas dobro razumijem.

So:

Main clause + jer-clause → comma before jer.
Jer-clause + main clause → comma after the jer-clause (i.e. at the end of that clause).

What is the difference between učitelj and učiteljica?

Both mean “teacher”, but they differ in gender:

učitelj – male teacher (masculine noun)
učiteljica – female teacher (feminine noun)

In the sentence, učiteljica clearly indicates a female teacher.

Examples:

Moj učitelj je jako strog. – My (male) teacher is very strict.
Moja učiteljica je jako draga. – My (female) teacher is very nice.

Adjectives and pronouns must agree:

dobra učiteljica – good (f.) teacher
dobar učitelj – good (m.) teacher
ona je učiteljica – she is a (female) teacher
on je učitelj – he is a (male) teacher

What is the difference between objašnjava and forms like objasni or objasnila je?

Here objašnjava is:

Present tense
3rd person singular
From objašnjavati – an imperfective verb meaning “to explain” in the sense of an ongoing or repeated action: “is explaining / explains”.

Aspect differences:

objašnjavati (imperfective) – focuses on the process or repeated action
- učiteljica objašnjava polako – the teacher explains (is explaining) slowly.
objasniti (perfective) – focuses on the completion / result
- učiteljica je objasnila lekciju – the teacher explained (has explained) the lesson (and it’s now done).
- učiteljica će objasniti lekciju – the teacher will explain the lesson (once, to completion).

In this sentence, we talk about an ongoing habit or current way of explaining, so objašnjava (imperfective present) is the natural choice.

Can I say učiteljica polako objašnjava instead of učiteljica objašnjava polako? Does the word order change the meaning?

Both are grammatically correct and mean basically the same:

učiteljica objašnjava polako – neutral order: “the teacher explains slowly”
učiteljica polako objašnjava – slightly more emphasis on polako, like “the teacher slowly explains” (highlighting how she does it).

Croatian allows adverbs like polako to move:

Učiteljica objašnjava polako.
Učiteljica polako objašnjava.

The difference is subtle and mostly about rhythm and emphasis, not basic meaning. In the given sentence, učiteljica objašnjava polako is the most straightforward neutral word order.

Why is it danas and not something like daneš (like “today’s”)? What part of speech is danas?

danas is an adverb meaning “today” (referring to time). It doesn’t change its form:

Danas je to lako. – Today this is easy.
Danas puno radim. – I work a lot today.
Sve danas dobro razumijem. – I understand everything well today.

There is a related adjective današnji – “today’s”:

današnji sat – today’s class / today’s lesson
današnji sastanak – today’s meeting

So:

danas = today (adverb of time)
današnji = today’s (adjective)

In the sentence, danas modifies the whole situation “understand everything well” and answers “when?”, so it must be the adverb form.