Diante do problema, pedi ajuda.

Here, diante de has a figurative meaning, not a literal one.

• Literal: in front of
• Figurative: faced with, in the face of, when confronted with

So diante do problema means something like faced with the problem or when confronted with the problem.

It sounds a bit more formal or literary than some everyday alternatives.

Because do is the contraction of de + o.

• de + o = do
• de + a = da
• de + os = dos
• de + as = das

Since the expression is diante de and problema takes the article o, you get:

• diante de o problema → diante do problema

This kind of contraction is very common in Portuguese.

Because problema is a masculine noun: o problema.

In Portuguese, many nouns of Greek origin ending in -ma are masculine, for example:

• o problema
• o sistema
• o tema
• o programa

So in this sentence, problema is masculine, which is why you see do problema.

Pedi is the preterite form of pedir for eu.

• pedir = to ask for
• eu pedi = I asked for / I requested

The preterite is used for a completed action in the past. So pedi ajuda means I asked for help as a finished event.

Compare:

• pedi ajuda = I asked for help
• pedia ajuda = I was asking for help / I used to ask for help

Because Portuguese often omits the subject pronoun when the verb already makes the subject clear.

• pedi clearly shows eu in this context

So:

• Diante do problema, pedi ajuda.
• Diante do problema, eu pedi ajuda.

Both are correct, but leaving out eu is very natural in Portuguese.

Because in Portuguese, the normal expression is pedir ajuda.

So you say:

• pedir ajuda = to ask for help

Not usually:

• pedir por ajuda ✘

This is a very important difference from English. English uses ask for help, but Portuguese usually just uses the verb directly with the noun:

• pedi ajuda
• ela pediu ajuda
• precisamos pedir ajuda

Because pedi ajuda is a very natural, general way to say I asked for help.

Portuguese often leaves out the article with abstract or general nouns in expressions like this.

• pedi ajuda = I asked for help

You could sometimes hear pedi uma ajuda, especially in informal speech, but it sounds more like I asked for a bit of help / a favor. The version without the article is the most neutral and standard here.

Not by itself. Pedi ajuda only tells us that the speaker asked for help. It does not say from whom.

If you want to say who the help was requested from, you can add that:

• Pedi ajuda ao meu amigo. = I asked my friend for help.
• Pedi ajuda à professora. = I asked the teacher for help.

So the sentence is complete as it is, but it leaves that detail unspecified.

Because Diante do problema is an introductory phrase that sets the context for the main action.

The comma helps separate:

• the situation/context: Diante do problema
• the main action: pedi ajuda

In short, it works a lot like an English comma after an opening phrase, as in:

• Faced with the problem, I asked for help.

In Portuguese, this comma is very natural here.

Yes, it is natural, but it sounds a bit more formal or written because of diante do problema.

In everyday conversation, Brazilians might also say things like:

• Quando vi o problema, pedi ajuda.
• Quando apareceu o problema, pedi ajuda.
• Com esse problema, pedi ajuda.

So the sentence is correct and natural, but slightly more polished in tone.

Yes, but the meaning or emphasis may shift slightly.

For example:

• Diante do problema, pedi ajuda.
  This sounds natural and emphasizes the situation first.

• Pedi ajuda diante do problema.
  This is less natural in this figurative sense and may sound a bit awkward.

Portuguese often puts context-setting phrases like diante do problema at the beginning, especially in more formal writing.

In Brazilian Portuguese, pedi is usually pronounced approximately like peh-JEE.

A few notes:

• the stress is on the last syllable: pe-DI
• in many Brazilian accents, di sounds a bit like jee

So pedi often sounds close to peh-JEE, though the exact sound can vary by region.

No. Diante de can be either literal or figurative.

Literal:

• Ele parou diante da porta. = He stopped in front of the door.

Figurative:

• Diante da crise, mudamos os planos. = Faced with the crisis, we changed the plans.

In your sentence, it is clearly figurative: faced with the problem.