Нам пора бы закончить этот рисунок до прихода гостей.

Because пора uses the dative case for the person who is affected.

So Russian structures this idea as something like:

• Нам пора закончить... = It is time for us to finish...
• Мне пора идти. = It’s time for me to go.
• Тебе пора спать. = It’s time for you to sleep.

So нам is not the subject in the English sense. It is more like to us.

There is no missing verb in modern Russian. Пора can act as the predicate by itself.

Russian often omits the present-tense form of to be, and with words like пора, that is completely normal:

• Мне пора. = It’s time for me to go / I have to go now.
• Нам пора закончить. = It’s time for us to finish.

So this is a complete sentence as it stands.

Пора means something like:

• it’s time
• it’s about time
• it’s time to

In this sentence, it introduces the idea that the action should happen now or soon.

A common pattern is:

кому? + пора + infinitive

For example:

• Мне пора работать.
• Нам пора уходить.
• Ему пора учиться.

So Нам пора закончить... means It’s time for us to finish...

Бы softens the statement and adds a nuance like:

• we really should
• it would be a good idea now
• it’s about time
• sometimes a mild sense of we’re a bit late already

Compare:

• Нам пора закончить = more direct: It’s time for us to finish
• Нам пора бы закончить = softer, more suggestive, often like We really ought to finish

So бы makes it sound less like a plain statement of fact and more like a recommendation, gentle push, or mild reproach.

Because закончить is perfective, and the sentence is about completing the drawing before a deadline.

Here the important idea is the result:

• finish it
• get it done
• bring it to completion

That is why закончить is natural.

If you used заканчивать instead, it would sound more like focusing on the process or on repeated/ongoing action, which is not the main point here.

So:

• закончить = to finish, to complete
• заканчивать = to be finishing / to finish in an ongoing or repeated sense

With до прихода гостей, Russian strongly prefers the perfective, because the action needs to be completed before something else happens.

It is the accusative case, because рисунок is the direct object of закончить.

We ask:

• закончить что? → этот рисунок

Since рисунок is masculine singular inanimate, its accusative form looks the same as the nominative:

• nominative: этот рисунок
• accusative: этот рисунок

So even though the form looks unchanged, it is functioning as an accusative object here.

Not always. Рисунок can mean:

• drawing
• sketch
• picture
• sometimes illustration
• even pattern/design in some contexts

In this sentence, drawing is probably the most natural translation, but the exact English word depends on context.

This phrase means before the guests’ arrival or more naturally before the guests arrive.

Breakdown:

• до = before / until
• прихода = genitive singular of приход (arrival)
• гостей = genitive plural of гости (guests)

Important points:

1. До requires the genitive case.
2. Приход is a noun meaning arrival.
3. Гостей depends on прихода, meaning arrival of the guests.

So literally it is:

before the arrival of the guests

Yes, absolutely.

Compare:

• до прихода гостей = before the guests’ arrival
• до того, как придут гости = before the guests come / before the guests arrive

The difference is mostly stylistic:

• до прихода гостей is more compact and noun-based
• до того, как придут гости is more clause-based and often feels more conversational or explicit

Both are correct.

In Russian, бы is a particle, and its position is somewhat flexible, but it usually appears near the word or phrase it is modifying.

Here пора бы is a very common and natural combination.

So:

• Нам пора бы закончить... sounds natural
• Нам бы пора закончить... is also possible, but the emphasis shifts slightly
• Нам пора закончить бы... would sound unnatural

For learners, it is safest to remember пора бы as a set phrase.

Not quite as strong as must.

The tone is usually something like:

• We should really finish this drawing before the guests arrive.
• We ought to finish this drawing before the guests arrive.
• It’s about time we finished this drawing before the guests arrive.

So it suggests:

• urgency
• practical necessity
• maybe mild pressure

But it is not as strict or forceful as Мы должны... or Нам нужно обязательно...

The given order is fairly natural and neutral:

Нам пора бы закончить этот рисунок до прихода гостей.

But Russian word order is flexible, so you could move things around for emphasis:

• До прихода гостей нам пора бы закончить этот рисунок.
  Emphasis on the deadline.

• Этот рисунок нам пора бы закончить до прихода гостей.
  Emphasis on this drawing.

The basic meaning stays the same, but the focus changes. In most cases, keeping пора бы together is the most natural choice.