Eu sugiro que a gente faça a reserva hoje para não adiar a viagem de novo.

Because sugerir que normally triggers the subjunctive in Portuguese.

So after Eu sugiro que..., Portuguese expects:

• que a gente faça = that we do / that we make

Not:

• que a gente faz = indicative, which sounds wrong here
• que a gente fazer = infinitive, also wrong in this structure

This is a very common pattern:

• Eu quero que você venha.
• Ela pede que eles esperem.
• Nós sugerimos que vocês saiam cedo.

So in your sentence, faça is the present subjunctive form of fazer.

Because a gente means we in everyday Brazilian Portuguese, but grammatically it behaves like third person singular.

So you get:

• a gente faz
• a gente quer
• a gente vai
• a gente faça in the subjunctive

Even though the meaning is we, the verb agrees as if it were he/she/it.

Compare:

• Nós fazemos a reserva. = We make the reservation.
• A gente faz a reserva. = We make the reservation.

Both are correct, but a gente is more common in spoken Brazilian Portuguese.

Yes. A more formal or less colloquial version would be:

• Eu sugiro que nós façamos a reserva hoje para não adiar a viagem de novo.

This is fully correct, but it sounds more formal or more written.

In everyday Brazilian speech, many people would prefer:

• Eu sugiro que a gente faça...

So the difference is mostly about register:

• a gente = very common, natural, conversational
• nós = also correct, but often more formal or careful

Yes, Eu can be omitted.

Portuguese often drops subject pronouns because the verb already shows the person:

• Sugiro que a gente faça a reserva hoje...

That sounds perfectly natural.

Including Eu can add:

• emphasis
• contrast
• clarity

For example:

• Eu sugiro que a gente faça a reserva hoje, mas ele prefere esperar.

So Eu is not necessary, but it is not wrong either.

A reserva means the reservation or the booking.

Depending on context, it could refer to:

• a hotel booking
• a flight reservation
• a restaurant reservation
• some other travel-related booking

In Brazilian Portuguese, fazer a reserva is a very normal expression meaning to make the reservation / booking.

You could also hear:

• fazer uma reserva
• reservar

For example:

• Vamos fazer a reserva hoje.
• Vamos reservar hoje.

Both are natural.

Both are possible.

These are both natural:

• fazer a reserva
• reservar

The version with fazer is extremely common because Portuguese often uses fazer + noun where English might prefer a single verb.

Examples:

• fazer uma pergunta = ask a question
• fazer uma ligação = make a call
• fazer uma reserva = make a reservation

So fazer a reserva is just a very idiomatic and common way to say it.

Because para + infinitive is commonly used when the subject is the same or understood in a general way.

Here, the sentence means:

• I suggest that we make the reservation today in order not to postpone the trip again.

Portuguese often prefers:

• para não adiar

instead of the more explicit:

• para que a gente não adie

Both can be correct, but para não adiar is simpler and more natural here.

So:

• para + infinitive = very common for in order to / so as to
• para que + subjunctive = also possible, often when the clause needs a clearer subject or sounds more formal

Because não normally comes right before the verb it negates.

So:

• para não adiar a viagem

means:

• so as not to postpone the trip

If you moved não somewhere else, it would sound unnatural or change the structure.

This is the standard pattern:

• para não esquecer
• para não chegar tarde
• para não perder o voo

Both can mean again, but de novo is more common in everyday Brazilian Portuguese.

So:

• adiar a viagem de novo = postpone the trip again
• adiar a viagem novamente = postpone the trip again

Difference in tone:

• de novo = more conversational, very common in speech
• novamente = a bit more formal or written

There is also a small nuance some people mention:

• de novo can sometimes feel like again / one more time
• novamente can sound slightly more neutral or formal

But in many real situations, they are interchangeable.

Yes, there is a difference.

• adiar = to postpone, put off, reschedule for later
• atrasar = to delay, be late, make something run late

In this sentence, adiar a viagem means the trip itself would be moved to a later date.

If you said atrasar a viagem, that could sound more like the trip is delayed rather than officially postponed.

So adiar is the better choice for:

• putting the trip off
• postponing it again

You may also hear postergar, but that is usually more formal or less common in everyday speech.

Yes, in informal Brazilian Portuguese, pra is very common.

So in speech, many people would say:

• Eu sugiro que a gente faça a reserva hoje pra não adiar a viagem de novo.

That sounds very natural in conversation.

Difference in style:

• para = standard, neutral, better for writing
• pra = informal, common in speech and casual writing

Yes, that is also possible:

• Eu sugiro fazer a reserva hoje para não adiar a viagem de novo.

This means roughly:

• I suggest making the reservation today...

This version is a little less explicit about who will do it, although it usually still implies we from context.

Compare:

• Eu sugiro que a gente faça... = I suggest that we do it
• Eu sugiro fazer... = I suggest doing it

Both are natural. The original sentence is slightly more explicit and personal because it includes a gente.

It is mostly neutral-to-informal.

Why:

• a gente makes it more conversational
• the rest of the sentence is standard and natural
• Eu sugiro que... is polite and normal, not slangy

So it would work well in:

• everyday conversation
• texting
• casual planning with friends or family
• normal spoken Brazilian Portuguese

If you wanted it to sound more formal, you might say:

• Sugiro que façamos a reserva hoje para não adiarmos a viagem novamente.

That sounds more formal and more written.

Yes: it combines several very common Portuguese patterns in one sentence.

1. sugerir que + subjunctive

   • Eu sugiro que... faça

2. a gente meaning we, but taking singular verb forms

   • a gente faça

3. fazer a reserva

   • common idiomatic expression

4. para + infinitive

   • para não adiar

5. de novo

   • everyday way to say again

So this is a very useful model sentence for learning how natural Brazilian Portuguese is often built.