بالكاد تتحرك السيارة.

بالكاد is an adverbial expression meaning barely / hardly / scarcely. Putting it first is very natural in Arabic when you want to foreground that idea.

So:

بالكاد تتحرك السيارة
= The car is barely moving

Starting with بالكاد gives the sentence a strong “only with great difficulty / almost not” feel right away.

For a learner, it is best to treat بالكاد as a fixed expression meaning:

• barely
• hardly
• scarcely

A very literal word-for-word breakdown is usually not helpful here. In real usage, you should learn it as one chunk: بالكاد.

Examples:

• بالكاد أسمعه = I can barely hear him
• بالكاد وصلنا = We barely arrived

Because السيارة is grammatically feminine in Arabic, and the verb agrees with it.

• السيارة = the car
• It is feminine, so the verb is feminine too.
• Therefore: تتحرك = it moves / is moving for a feminine subject

If the subject were a masculine noun, you would normally use يتحرك instead.

For example:

• يتحرك القطار = The train is moving
• تتحرك السيارة = The car is moving

Yes. In Arabic, the subject often comes after the verb.

So in:

تتحرك السيارة

the verb is تتحرك and the subject is السيارة.

This is a very normal Arabic sentence pattern, especially in Modern Standard Arabic.

Arabic commonly uses both patterns:

• تتحرك السيارة
• السيارة تتحرك

Both can mean The car is moving.

But there is often a nuance:

• تتحرك السيارة sounds like a straightforward verbal sentence.
• السيارة تتحرك puts more attention on the car as the topic.

With بالكاد, both are possible:

• بالكاد تتحرك السيارة
• السيارة بالكاد تتحرك

The version you were given is very natural and stylistically smooth.

تتحرك is in the imperfect form. In English, the Arabic imperfect can correspond to:

• moves
• is moving
• sometimes does move, depending on context

In this sentence, English most naturally uses the progressive:

• The car is barely moving

So even though Arabic uses one verb form, English may translate it with is moving.

Because Arabic does not need a separate present-tense is here.

The verb تتحرك already means:

• moves
• is moving

So Arabic does not say something like is move. The single verb already carries the present meaning.

That is why:

بالكاد تتحرك السيارة

naturally means The car is barely moving, even without a separate word for is.

The verb comes from تحرّك = to move

Its imperfect form is يتحرّك / تتحرّك.

The initial تـ here marks a form used with a feminine singular subject, among other uses. In this sentence it matches السيارة, which is feminine.

So:

• هي تتحرك = She/it is moving
• السيارة تتحرك = The car is moving

Also note the doubled ر sound in تتحرّك because of the shadda.

Not exactly.

• بالكاد = barely / hardly
  → emphasizes that something happens only a little, almost not at all

• بصعوبة = with difficulty
  → emphasizes effort or difficulty

Compare:

• بالكاد تتحرك السيارة = The car is barely moving
• تتحرك السيارة بصعوبة = The car moves with difficulty

These are similar, but not identical.
بالكاد is stronger in the sense of almost not moving.

A rough pronunciation is:

bil-kād tataḥarraku as-sayyāra(h)

A few notes:

• بالكاد → bil-kād
• تتحرك → tataḥarrak
• السيارة → as-sayyāra

In السيارة, the ال is pronounced as- because س is a sun letter, so the l sound assimilates.

Also, in normal written Arabic, short vowels are usually not written, so you see:

بالكاد تتحرك السيارة

without vowel marks.

Yes. That is also correct and natural.

Compare:

• بالكاد تتحرك السيارة
• السيارة بالكاد تتحرك

Both mean the same thing. The difference is mainly one of emphasis and style:

• بالكاد تتحرك السيارة foregrounds barely
• السيارة بالكاد تتحرك foregrounds the car

Both are good Modern Standard Arabic.

In careful vocalization, you would typically see:

بالكادِ تتحرّكُ السّيّارةُ

But in most real-world Arabic writing, these short vowels are omitted, so you normally just see:

بالكاد تتحرك السيارة

That is completely normal. Learners should get used to reading unvocalized text, since that is the standard in newspapers, books, and most everyday writing.