A fita adesiva ajudou por um momento, mas a fenda abriu-se outra vez.

It means adhesive tape, sticky tape, or simply tape, depending on context.

A few useful notes:

• fita = tape/ribbon
• adesiva = adhesive, sticky

So fita adesiva is a fairly general term. It does not automatically mean a specific kind of tape such as duct tape.

Because fita and fenda are both feminine singular nouns, so they take the definite article a, meaning the.

• a fita adesiva = the adhesive tape
• a fenda = the crack / the split

In this sentence, Portuguese and English both use the definite article naturally.

They are in the pretérito perfeito simples, which is the normal simple past tense for completed actions in European Portuguese.

• ajudou = helped
• abriu-se = opened / opened up

This tense presents the events as finished:

• the tape helped
• then the crack opened again

It means for a moment or briefly.

So ajudou por um momento means the tape was useful only temporarily.

This is a very natural expression. In this sentence, por um momento sounds more idiomatic than a more literal phrase like durante um momento.

Yes. Portuguese uses ajudar much like English does in sentences such as That helped for a bit.

Here, a fita adesiva ajudou does not mean the tape solved the problem completely. It means it improved the situation temporarily.

Possible English equivalents would be:

• The tape helped for a moment
• The tape held things together for a moment
• The tape worked briefly

So ajudou is perfectly natural.

Fenda usually means a crack, split, gap, or fissure, depending on the context.

It suggests some kind of opening in a surface or material. In this sentence, crack or split would be the most natural English choices.

It is a little more neutral and general than some other words that refer to damage in a surface.

The se is part of the verb form abrir-se, which is commonly used when something opens or becomes open.

It is not usually translated literally as itself in natural English. Instead, it helps express the idea that the thing opened up.

Compare:

• Ele abriu a porta. = He opened the door.
• A porta abriu-se. = The door opened.

So:

• a fenda abriu-se outra vez = the crack opened up again

Because in European Portuguese, in a normal affirmative main clause, clitic pronouns like se usually come after the verb. This is called enclisis.

So:

• abriu-se is the expected European Portuguese order

You often get se before the verb in cases such as:

• não se abriu = it didn’t open
• quando se abriu = when it opened

A learner may notice that se abriu is much more common in Brazilian Portuguese, but abriu-se fits Portugal Portuguese very well.

Outra vez means again.

Yes, it is very close to de novo. In many situations, they are interchangeable.

• outra vez = again
• de novo = again
• novamente = again, but often a bit more formal

In everyday speech, outra vez is very common. It can sometimes feel slightly more emphatic, like again / yet again.

Yes, you could.

• A fenda abriu-se outra vez = The crack opened again
• A fenda reabriu-se = The crack reopened

The version with outra vez is a little more explicit and conversational.
The version with reabriu-se is shorter and more compact.

Both are correct; the original sentence just chooses the more transparent everyday phrasing.

The most neutral order here is exactly what you see:

• abriu-se outra vez

That places outra vez after the verb phrase, which is very natural in Portuguese.

You can move outra vez in some contexts for emphasis, but the sentence as given is the most straightforward and idiomatic version for a learner to remember.