Learn Hardcore Italian: Metterò un segnalibro nuovo nel tuo quaderno, così non perderai la pagina. - I will put a new bookmark in your notebook so you won’t lose the page.

Metterò is the first‐person singular future simple of mettere (“to put”). It tells the listener that the action will take place in the future. If you said Metto un segnalibro nuovo…, that would sound like you’re doing it right now (present). Using metterò makes it clear you intend to do it later or very soon.

Why do we use un before segnalibro and not uno?

In Italian, uno is used only before masculine nouns beginning with z, s+consonant, gn, ps, x, y (e.g. uno studente, uno zaino). Segnalibro begins with s-e (s+vowel), so we use un, the regular masculine indefinite article: un segnalibro.

Why is there a definite article in nel tuo quaderno? In English we don’t say “in the your notebook.”

Italian normally requires a definite article before possessive adjectives (except with some family members in the singular). So you say il tuo quaderno. When you combine in + il, you get nel. Hence nel tuo quaderno = “in your notebook.”

What does così mean here? Could we use perché or affinché instead?

Here così means “so that” or “in such a way that.” It introduces a purpose: “I will put a new bookmark in your notebook, so that you won’t lose the page.” You could say perché non perda or affinché non perda, but then you must use the subjunctive, and affinché often sounds more formal. Così + indicative is common in everyday speech.

Why is the verb in the second clause non perderai (future indicative) and not the subjunctive?

When così introduces a clause of purpose and the subject of both verbs is the same (here “you”), Italian uses the indicative rather than the subjunctive. Subjunctive would be required after affinché or perché if you keep non in a negative‐purpose sense, but with così + no che, stick to the indicative: non perderai.

Could we say un nuovo segnalibro instead of un segnalibro nuovo? Is there a difference?

Yes. Un nuovo segnalibro is more common and treats “new” as an inherent quality of the bookmark. Un segnalibro nuovo is also correct but puts nuovo after the noun, often to contrast it with an old one you might already have. In most contexts these two word orders are interchangeable.

Can I replace nel tuo quaderno with a pronoun like ci?

Absolutely. You can say:
Metterò un segnalibro nuovo ci, though more naturally:
Ci metterò un segnalibro nuovo, così non perderai la pagina.
Here ci stands for “in it” (i.e. in your notebook).

Could I shorten non perderai la pagina by using a direct‐object pronoun?

Yes. Pagína is feminine singular, so the pronoun is la. You can say:
…così non la perderai.

Why is segnalibro written as one word? Are there other terms?

Segnalibro is a compound noun (from segnare + libro) and is normally written solid. A common synonym is marcapagina (“page‐marker”), also one word. You can use either.

What does perdere la pagina literally mean? Is it an idiom?

Literally it means “to lose the page.” Idiomatically, it means “to lose your place” in a book or notebook. It’s perfectly natural in Italian, just as English speakers talk about “losing your place” rather than “misplacing the page.”