Пора бы отдохнуть, но мне ещё нужно ответить на сообщения.

It would be time to rest, but I still need to reply to messages.

Breakdown of Пора бы отдохнуть, но мне ещё нужно ответить на сообщения.

• на: to
• мне: me
• но: but
• нужно: to need
• ответить: to reply
• отдохнуть: to rest
• ещё: still
• бы: would
• сообщение: message
• пора: time

Questions & Answers about Пора бы отдохнуть, но мне ещё нужно ответить на сообщения.

What does Пора бы mean here, and why is бы used?

Пора means it’s time (to…). Adding бы makes it softer and more tentative: it would be time / it’s about time / I should probably….
So Пора бы отдохнуть is less blunt than Пора отдохнуть and often implies “ideally, now would be a good time to rest.”

Why is there no subject in Пора бы отдохнуть? Who is supposed to rest?

Russian often uses impersonal constructions. Пора works like “it’s time” in English, and the person is understood from context. If you want to specify, you can add a dative pronoun: Мне пора (бы) отдохнуть = “I should (probably) rest.”

Why is отдохнуть in the infinitive, and what aspect is it?

After пора, Russian uses an infinitive to name the action: пора + infinitive.
Отдохнуть is perfective: it means to have a rest / to rest (and finish that rest)—a single complete “rest break,” not the ongoing process.

Could you also say Пора бы отдыхать? What’s the difference?

Yes. Отдыхать is imperfective and focuses on the process: it would be time to be resting / to start resting (as an activity).
Пора бы отдохнуть (perfective) sounds like “I need a proper rest break,” while Пора бы отдыхать can sound like “I should be resting (instead of doing this).”

Why is there a comma before но?

Because но links two independent parts (two clauses) with contrasting ideas:
1) Пора бы отдохнуть
2) мне ещё нужно ответить на сообщения
In Russian, a comma is normally required before но in this structure.

What role does мне play in мне ещё нужно ответить…?

Мне is dative and marks who has the necessity/obligation. Russian often expresses “I need to…” as to me it is necessary:
мне нужно + infinitive = “I need to + verb.”

What is нужно grammatically? Is it a verb?

Нужно is a predicative word (often grouped with “category of state” words), not a normal verb. It functions like “necessary” in an impersonal predicate: (it is) necessary.
You can change tense with было/будет: мне было нужно (I needed), мне будет нужно (I will need).

Why is ответить perfective here?

Ответить is perfective and suggests completing the task: to reply (and be done with it). That fits a “to-do item” feeling: “I still need to reply to the messages.”
Imperfective отвечать would emphasize the process or repeated/ongoing replying.

What does ещё add, and where can it go?

Ещё means still / yet here: the task remains unfinished.
Word order can vary for focus:

• мне ещё нужно ответить… (neutral)
• мне нужно ещё ответить… (emphasis on “one more thing I need to do”)
• ещё нужно ответить… (more general, sometimes implying “there are still messages to reply to”).

Why is it ответить на сообщения and not ответить сообщения?

With ответить in this meaning, Russian typically uses на + accusative to mark what you are replying to: ответить на что? = “reply to what?”
So: на сообщения (accusative plural). Without the preposition, ответить сообщения is generally not correct in standard usage.

Could it be ответить сообщениям instead?

That would sound unusual. Dative (сообщениям) would mean “to the messages” as recipients, but messages aren’t really recipients.
If you want to express replying “to someone,” you use dative with a person: ответить ему/ей (reply to him/her). With messages, standard is ответить на сообщения.

What exactly does сообщения mean here—texts, DMs, emails?

Сообщение is broad: a message in an app, a text, a DM, sometimes an email (depending on context). In everyday speech, сообщения often implies chat/app messages unless the context suggests otherwise.