Postes elétricos caem, assim como redes elétricas falham.

This is very common in headline or news-style Portuguese. Articles like os and as are often dropped to make the sentence shorter and more direct.

In fuller, more neutral prose, you might expect:

Os postes elétricos caem, assim como as redes elétricas falham.

So the version without articles is not strange here; it just sounds more like a brief report or headline.

Assim como links the two parts of the sentence and shows a parallel idea.

Here it means something like:

• just as
• as well as
• likewise

It is a bit more structured and formal than simply using e.

So:

• Postes elétricos caem, e redes elétricas falham = more basic and
• Postes elétricos caem, assim como redes elétricas falham = the second idea is presented as a matching parallel to the first

Both are present indicative, third person plural.

• caem = from cair
• falham = from falhar

Even though they are present forms, Portuguese often uses the present in:

• general statements
• news reporting
• immediate, vivid description of events

So this can sound like either a general truth in context or a current-event report.

Because their subjects are plural:

• postes elétricos = plural, so caem
• redes elétricas = plural, so falham

Portuguese verbs must agree with their subject in number and person.

Compare:

• O poste elétrico cai.
• Os postes elétricos caem.

And:

• A rede elétrica falha.
• As redes elétricas falham.

Because adjectives in Portuguese usually agree with the noun they describe.

• poste is masculine → postes elétricos
• rede is feminine → redes elétricas

So the adjective changes form:

• masculine plural: elétricos
• feminine plural: elétricas

This kind of agreement is one of the basic patterns of Portuguese grammar.

In Portuguese, adjectives very often come after the noun, especially in straightforward descriptive phrases.

So:

• postes elétricos
• redes elétricas

is the normal order.

English often puts adjectives before the noun, but Portuguese commonly puts them after. You can move some adjectives before the noun in Portuguese, but that often changes the tone or meaning. Here, the post-noun position is the natural one.

In European Portuguese, caem is pronounced roughly like KAI-em, but very compressed in natural speech.

A few useful points:

• it is the form of cair
• the stress is on the first syllable
• the ending is not pronounced like plain English -em

If you are learning Portugal pronunciation, the final nasal sound may feel subtle. The important thing is not to pronounce it like two fully separate English syllables with a strong ee sound.

The accent mark in é shows two things:

1. Stress: the word is stressed on lé

   • e-LÉ-tri-cos
   • e-LÉ-tri-cas

2. Vowel quality: é is an open vowel

Without the accent, the stress and pronunciation would be different. Accent marks in Portuguese are very important because they often tell you exactly where the stress goes.

Sometimes Portuguese can omit repeated words if the meaning is completely clear, but here keeping elétricas is the safest and most natural option.

So:

• Postes elétricos caem, assim como redes elétricas falham.

is clear and balanced.

If you said:

• Postes elétricos caem, assim como redes falham.

it might still be understandable in context, but it sounds less complete and a bit less polished.

It depends on context.

Rede elétrica can refer to:

• an electrical network
• a power grid
• an electricity distribution system

It does not always mean a single physical wire or cable. If you specifically mean power lines, Portuguese might use terms like linhas elétricas or cabos elétricos, depending on context.

So redes elétricas falham suggests that the electrical system or network is failing, not necessarily just that individual wires are falling.

The comma helps separate the two parallel clauses:

• Postes elétricos caem
• assim como redes elétricas falham

It makes the sentence easier to read and highlights the comparison/parallel structure introduced by assim como.

In this kind of formal or report-like sentence, the comma is very natural.