Calul aleargă repede.

Romanian usually puts the definite article at the end of the noun, not before it as English does.

• cal = horse
• calul = the horse

So -ul is the masculine singular definite article here. This is one of the most noticeable features of Romanian grammar.

Because calul means the horse, while cal means just a horse / horse depending on context.

Compare:

• Calul aleargă repede. = The horse runs fast.
• Un cal aleargă repede. = A horse runs fast.

So if you want a specific horse, Romanian uses the definite form calul.

Aleargă is the 3rd person singular present tense form of the verb a alerga = to run.

It is used for:

• he runs
• she runs
• it runs

In this sentence, it matches calul, which is singular.

A few present-tense forms of a alerga:

• eu alerg = I run
• tu alergi = you run
• el/ea aleargă = he/she runs
• noi alergăm = we run
• voi alergați = you all run
• ei/ele aleargă = they run

Notice that el/ea and ei/ele both use aleargă.

Romanian often leaves out subject pronouns when they are not needed, because the verb form usually tells you the person and number.

So instead of saying:

• Calul el aleargă repede.

Romanian simply says:

• Calul aleargă repede.

Also, with a noun subject like calul, adding a pronoun would usually be unnecessary.

Repede is an adverb meaning fast / quickly. It describes how the horse runs.

So:

• aleargă = runs
• aleargă repede = runs fast

Unlike English, Romanian does not usually have a separate -ly ending like quickly. Many Romanian adverbs have their own fixed form, and repede is one of them.

The normal, neutral order here is:

• Calul aleargă repede.
• subject + verb + adverb

This is the most natural basic order.

But Romanian is more flexible than English, and other orders are possible for emphasis, such as:

• Repede aleargă calul.
• Aleargă repede calul.

These are more marked and depend on context or style. For a learner, Calul aleargă repede is the safest standard pattern.

A simple learner-friendly pronunciation guide would be:

• Calul ≈ KAH-lool
• aleargă ≈ ah-leh-AR-guh
• repede ≈ REH-peh-deh

A few useful notes:

• c before a sounds like k
• ă is a short central vowel, something like the a in sofa
• Romanian r is usually trilled or tapped
• Stress is roughly:
  • CAlul
  • aleARgă
  • REpede

In this verb, -ă is part of the present-tense ending for the 3rd person singular form.

Romanian verbs change their endings depending on the subject. So a alerga becomes:

• alerg = I run
• alergi = you run
• aleargă = he/she/it runs

So the -ă helps show the grammatical form of the verb.

In a simple sentence like this, repede most commonly comes after the verb:

• Calul aleargă repede.

That is the most natural order for beginners to use.

Romanian can sometimes place adverbs before the verb for emphasis or style:

• Calul repede aleargă — possible in special contexts, but not the normal everyday version
• Repede aleargă calul — also possible, but more emphatic

So the safest rule is: after the verb in simple statements like this one.

Either can work, depending on the English style.

• Calul aleargă repede. = The horse runs fast.
• Calul aleargă repede. = The horse runs quickly.

In ordinary English, runs fast often sounds more natural than runs quickly, so fast is a very common translation here.

Cal is a masculine noun in Romanian. Yes, that matters, because the definite article and sometimes other words must agree with the noun.

Here:

• cal = horse
• calul = the horse

The ending -ul is the masculine singular definite article used with this noun.

If you later add adjectives, gender agreement will matter there too. For example:

• calul frumos = the beautiful horse

So learning the noun’s gender is important from the beginning.