Learn Hardcore Spanish (Spain): Que descanses; mañana seguimos con el proyecto. - Sleep well; tomorrow we’ll continue with the project.

Because it’s a conjunction introducing a wish, not an interrogative or exclamative word. Only the interrogative/exclamative form takes an accent (qué). Here you can even write exclamations as ¡Que descanses!, still without the accent on que.

What verb form is descanses, and why is the subjunctive used?

Descanses is the second-person singular present subjunctive of descansar. Spanish uses que + present subjunctive to express wishes, hopes, or good will: Que descanses, Que te vaya bien, Que tengas un buen día. Formation (regular -ar verbs): take the yo form (descanso), drop -o, add -e endings: descanse, descanses, descanse, descansemos, descanséis, descansen.

Could I just say Descansa instead of Que descanses?

Yes. Descansa is the tú imperative (“Rest.”). Que descanses sounds less like a command and more like a kind wish (“Hope you get some rest”). Both are common; Que descanses is especially common as a friendly sign-off at night.

How do I say it to more than one person or formally in Spain?

Informal plural (vosotros): Que descanséis.
Formal singular (usted): Que descanse.
Formal plural (ustedes): Que descansen. In Spain, vosotros is the default informal plural; ustedes is formal.

Can I add bien or use exclamation marks?

Absolutely:

¡Que descanses! / ¡Que descanses bien!
¡Buenas noches! ¡Que descanses! Spanish uses inverted exclamation marks: ¡…!

Is the semicolon necessary here? Could I use a period or a comma?

The semicolon neatly links two related clauses. You could also use a period: Que descanses. Mañana seguimos con el proyecto. A simple comma between two independent sentences is best avoided in formal writing; prefer semicolon or period. No capitalization after a semicolon in Spanish unless it’s a proper noun (mañana stays lowercase).

Does mañana mean “tomorrow” or “morning” here?

Here it means “tomorrow.” On its own, mañana can mean either, but with a verb like seguimos it’s understood as “tomorrow.” To specify the time of day, say:

Por la mañana = in the morning
Mañana por la mañana = tomorrow morning

Why is seguimos in the present if it’s about the future?

Spanish often uses the present for scheduled or near-future plans: Mañana seguimos = “We continue tomorrow.” You could also say:

Mañana seguiremos con el proyecto (simple future; a bit more distant or matter-of-fact)
Mañana vamos a seguir con el proyecto (colloquial, very common)

Do I need con after seguir? What’s the difference between seguir con and seguir + noun?

Seguir con + noun means “to continue with” something already in progress: Seguimos con el proyecto.
Seguir + direct object often means “to follow”: Sigo el proyecto en redes (“I follow the project online”). Using seguir con avoids that ambiguity when you mean “continue.”

Could I say seguir + gerund instead?

Yes: Mañana seguimos trabajando en el proyecto = “Tomorrow we’ll keep working on the project.” Seguir + gerundio emphasizes the ongoing activity; seguir con + noun emphasizes resuming/continuing the project as a whole. Both are natural.

Why el proyecto and not just proyecto?

Spanish normally uses a definite article with specific, known items: el proyecto = “the (particular) project” we’ve been discussing. Omit the article only in special contexts (headlines, labels) or if the reference is indefinite (un proyecto = “a project”).

What subject does seguimos express?

Seguimos is first-person plural (we). Spanish usually drops the subject pronoun unless needed for emphasis or contrast. You could say Nosotros seguimos mañana…, but it isn’t necessary.

How do I pronounce the tricky parts (que, mañana, seguimos)?

que: “keh” (the u is not present here; just ke)
mañana: ma-NYA-na (ñ = “ny” in canyon)
seguimos: seh-GEE-mohs; the u in gui is silent and simply keeps g as a hard/soft g sound (not like English “j”); g between vowels is a softer stop/fricative in Spanish.

Why not Que descansas or Que te descanses?

After que for wishes, you need the present subjunctive (descanses), not the indicative (descansas). And descansar isn’t reflexive in standard usage, so Que te descanses is nonstandard; say Que descanses.

Can I change the word order?

Yes. Both are natural:

Mañana seguimos con el proyecto.
Seguimos con el proyecto mañana. Fronting mañana often gives it a bit more emphasis (“As for tomorrow, we continue…”).

Any good synonyms for seguir here?

Mañana continuamos con el proyecto.
Mañana retomamos el proyecto. (resume after a pause)
Mañana volvemos a trabajar en el proyecto. Also common as a sign-off: Lo dejamos aquí; mañana seguimos.