Learn Hardcore French: Le spectacle commence dans une heure, alors je prépare mon stylo pour prendre des notes. - The show starts in an hour, so I prepare my pen to take notes.

In French every noun has a gender (masculine or feminine). Spectacle is a masculine noun, so you use the masculine definite article le. You just have to memorize that le spectacle (the show) is masculine.

Why do we use dans une heure instead of en une heure?

Dans une heure means “in one hour” – it tells you when something will happen (one hour from now).
By contrast, en une heure means “in one hour” as a duration (how long it takes).
Example:
• Le film commence dans une heure. (The movie starts in an hour.)
• J’ai lu ce livre en une heure. (I read that book in one hour.)

Why is there no à before commence? I thought French uses commencer à.

You only use commencer à when you attach a verb or a clock time directly:
• Le spectacle commence à 20 h (The show starts at 8 PM).
Here, because you’ve already used dans une heure to give the start time, you don’t add another à.

How is alors used here? Could it mean then or so?

In this sentence alors functions as so (a connector showing consequence). You could translate it as “so” or “therefore.” It links the fact that the show starts soon to the action of preparing your pen.

Why is the verb prépare in the simple present tense, and how should I translate it?

French uses the simple present (je prépare) for both a general action and what’s happening right now. You translate it depending on context:
• Here it’s equivalent to English present continuous: “I’m getting my pen ready” or simply “I prepare my pen.”

Why mon stylo instead of un stylo?

Using mon (my) indicates you’re preparing your own pen—something you possess. If you said un stylo, it’d sound like “I prepare a pen” (any pen), which is less natural when you mean your personal writing tool.

What does pour prendre des notes mean and why do we use pour + infinitive?

Pour + infinitive expresses purpose (in order to).
So pour prendre des notes means “in order to take notes.” It answers the question Why are you preparing your pen?

Why is notes plural and preceded by des?

Notes are counted in plural (you usually take more than one). Des is the plural indefinite article (some notes). It’s used when you don’t specify an exact number.