Inače idem pješice na posao, ali danas idem autobusom.

Inače means normally, usually, as a rule, or under normal circumstances.

In this sentence, it contrasts the speaker’s usual habit with what is happening today:

• Inače idem pješice na posao = I usually go to work on foot
• ali danas idem autobusom = but today I’m going by bus

So inače is a very natural way to introduce someone’s normal routine.

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

Here, idem means I go / I am going, so the subject I is already built into the verb ending -m.

• idem = I go
• ideš = you go
• ide = he/she/it goes

You could say Ja inače idem pješice na posao..., but ja would add emphasis, like I usually walk to work.

Because Croatian normally states the verb in each clause:

• Inače idem pješice na posao
• ali danas idem autobusom

In English, we might sometimes avoid repetition, but in Croatian this repetition is completely natural.

The second idem makes the contrast very clear:

• usually: I go on foot
• today: I go by bus

You may sometimes hear omissions in casual speech if the meaning is obvious, but repeating the verb here is the standard and clearest option.

Pješice means on foot or by walking.

It is an adverb, not a noun or adjective. So it describes how someone goes somewhere.

Examples:

• Idem pješice. = I’m going on foot.
• Do škole idem pješice. = I go to school on foot.

A learner might expect something more like by feet, but Croatian uses pješice as a fixed adverbial form.

This is an idiomatic expression in Croatian:

• ići na posao = to go to work
• biti na poslu = to be at work

Even though na often means onto or on, with posao it is the normal preposition for this expression.

So:

• Idem na posao. = I’m going to work.
• On je na poslu. = He is at work.

Using u posao here would not sound natural for the meaning to go to work.

Because it is in the instrumental case.

In Croatian, means of transport are often expressed with the instrumental case, without a preposition:

• autobusom = by bus
• vlakom = by train
• tramvajem = by tram
• autom = by car

So:

• idem autobusom = I’m going by bus

This is one of the most useful patterns to learn early:

• ići + instrumental for transport

Because Croatian often expresses transport without a preposition by using the instrumental case alone.

English says:

• by bus
• by train
• by car

Croatian usually says:

• autobusom
• vlakom
• autom

So the idea of by is already contained in the case form.

Yes, idem is present tense.

Croatian present tense can be used:

1. for a habitual action
2. for what is happening now
3. for a planned or current situation

So in this sentence:

• Inače idem pješice na posao = a habitual action
• danas idem autobusom = what is happening today / the plan for today

This is very similar to English, where we might say:

• I usually walk to work, but today I’m going by bus

Sometimes, but the meaning shifts a little.

• idem pješice na posao = I go to work on foot
• hodam na posao literally suggests I walk to work

In many contexts they are similar, but idem pješice focuses more clearly on the means of going rather than the physical action of walking itself.

For beginners, idem pješice na posao is a very safe and natural choice.

Ali means but.

It connects two contrasting ideas:

• Inače idem pješice na posao
• ali danas idem autobusom

So it marks the contrast between the usual routine and today’s exception.

This is a very common conjunction in Croatian.

Yes, Croatian word order is more flexible than English word order, but some versions sound more natural than others.

The original sentence is very natural:

• Inače idem pješice na posao, ali danas idem autobusom.

You might also hear:

• Inače na posao idem pješice, ali danas idem autobusom.
• Danas idem autobusom, ali inače idem pješice na posao.

The meaning stays basically the same, but the focus changes slightly depending on what comes earlier.

For learners, the original word order is an excellent model.

It is neutral and natural in both speech and writing.

Nothing in it is especially slangy or especially formal. It would sound normal in everyday conversation, in class examples, or in ordinary writing.

That makes it a very useful sentence pattern to learn.

A very useful pattern is:

Inače idem [method/place], ali danas idem [different method/place].

For example:

• Inače idem autom na posao, ali danas idem vlakom.
• Inače idem autobusom u školu, ali danas idem pješice.
• Inače ručam kod kuće, ali danas ručam u restoranu.

So this sentence is great for learning how to contrast:

• usual habit with
• today’s situation