Înainte de a se înscrie, Ana consultă catalogul.

Înainte de a means before doing something or before someone does something.

In Romanian, when înainte de is followed by a verb, you normally use a:

• înainte de a pleca = before leaving / before he/she leaves
• înainte de a se înscrie = before enrolling / before she enrolls

So the pattern is:

• înainte de + noun
  înainte de curs = before the class
• înainte de a + verb
  înainte de a se înscrie = before enrolling

That a is a grammatical marker used before the infinitive/subjunctive-type verb construction in this pattern.

Because a se înscrie is a reflexive verb, meaning to enroll/sign up (oneself).

So:

• a înscrie = to register/enroll someone or something
• a se înscrie = to register/enroll oneself, so to sign up / to enroll

Examples:

• Universitatea îl înscrie pe student.
  = The university enrolls the student.
• Studentul se înscrie.
  = The student enrolls / signs up.

In your sentence, Ana is the one doing the action for herself, so Romanian uses the reflexive form: se înscrie.

No. In de a se înscrie, înscrie is not a plain infinitive in the same way English uses to enroll.

Romanian often uses this structure:

• de a + verb form

In modern grammar, this is usually analyzed as a construction with a plus the subjunctive-like form of the verb, especially in fixed patterns such as înainte de a...

So for learners, the safest practical rule is:

• Learn înainte de a + verb as a set pattern meaning before doing / before someone does

You do not need to treat înscrie here as an ordinary dictionary infinitive. The dictionary form is a se înscrie.

Because Înainte de a se înscrie is an introductory subordinate clause.

The sentence is structured like this:

• Înainte de a se înscrie = subordinate clause
• Ana consultă catalogul = main clause

Romanian normally separates this kind of introductory clause with a comma:

• Înainte de a se înscrie, Ana consultă catalogul.

This is very similar to English punctuation in:

• Before enrolling, Ana checks the catalog.

Yes, consultă comes from a consulta.

Depending on context, it can mean:

• to consult
• to check
• to look at
• to refer to

In this sentence, consultă catalogul most naturally means something like:

• checks the catalog
• looks through the catalog
• consults the catalog

Romanian often uses a consulta in formal or academic contexts for checking a document, list, or source of information.

Because catalogul means the catalog.

Romanian usually puts the definite article at the end of the noun:

• catalog = a catalog
• catalogul = the catalog

This is one of the big differences from English. Instead of a separate word like the, Romanian attaches it to the noun.

More examples:

• student = student
• studentul = the student
• profesor = teacher
• profesorul = the teacher

So Ana consultă catalogul = Ana consults/checks the catalog.

Yes, Romanian often drops subject pronouns, but here Ana is a noun, not a pronoun, and it is included because the speaker wants to identify who is doing the action.

Romanian verbs often already show the person:

• consult = I consult
• consulți = you consult
• consultă = he/she consults

But consultă could mean he/she consults, so using Ana makes it clear who the subject is.

If the context were already very clear, Romanian could sometimes avoid repeating the name in nearby sentences, but in a standalone sentence it is perfectly natural to say Ana consultă catalogul.

Romanian uses the present tense here because it is stating a general or narrative action sequence.

• Ana consultă catalogul = Ana checks/consults the catalog

This can describe:

1. a habitual action
2. a general procedure
3. a narrative event in present tense

English often does the same:

• Before enrolling, Ana checks the catalog.

So there is no mismatch. Both languages can use the present tense for this kind of statement.

Both are possible.

• to enroll is often better in academic or official contexts
• to sign up is more everyday and informal

Because the sentence mentions catalogul, which sounds academic or administrative, to enroll is often the best choice.

So:

• Înainte de a se înscrie = Before enrolling
• or Before signing up

The best translation depends on the context.

In this sentence, yes, the natural interpretation is that it refers to Ana, because she is the subject of the main clause and there is no other person mentioned.

So the sentence is understood as:

• Before she enrolls, Ana consults the catalog
• or more naturally, Before enrolling, Ana consults the catalog

Romanian often leaves this kind of subject understood from context. If there were another possible person, the sentence might need to be rewritten to avoid ambiguity.

A rough pronunciation guide is:

• Înainte ≈ uhn-NIGHN-te
• de ≈ deh
• a ≈ ah
• se ≈ seh
• înscrie ≈ uhn-SKREE-eh

A few useful notes:

• î and â represent a central vowel that English does not really have
• ă is a short, reduced vowel, somewhat like the a in sofa
• ie at the end of înscrie is pronounced as two vowels, roughly ee-eh

This is only approximate, but it helps you get close.

Yes, absolutely.

Both are natural:

• Înainte de a se înscrie, Ana consultă catalogul.
• Ana consultă catalogul înainte de a se înscrie.

The difference is mainly emphasis and style:

• putting Înainte de a se înscrie first emphasizes the time relation first
• putting it at the end makes the main action come first

Both mean essentially the same thing.