Learn Hardcore Spanish (Latin America): El gerente firmará el documento y luego lo citará como ejemplo en la conferencia. - The manager will sign the document and then will quote it as an example in the conference.

Firmará is the third-person singular simple future tense of firmar ( to sign ). In Spanish the simple future expresses actions that will happen. It is formed by adding the endings -é, -ás, -á, -emos, -éis, -án directly to the infinitive:
firmar + á = firmará

Why is there no subject pronoun before firmará?

Spanish often drops the subject pronoun because the verb ending makes the subject clear. Firmará already indicates that he, she or you (formal) will sign, so él, ella or usted is optional and usually omitted unless you need emphasis or contrast.

What does lo refer to in lo citará, and why not le?

Lo is a direct object pronoun that replaces el documento, which is masculine and singular. Direct objects use lo (masc.) or la (fem.). Le is for indirect objects, so here you need lo to say he will cite it.

Could we avoid the pronoun and repeat the noun with citará el documento?

Yes, you can say citará el documento. However, using lo makes the sentence more concise and natural once el documento has already been mentioned.

Could we use va a firmar instead of firmará?

Absolutely. El gerente va a firmar el documento uses the periphrastic future ( ir a + infinitive ) and is very common in spoken Spanish. It conveys the same meaning (he is going to sign).

What is the difference between luego and después here?

Both mean after or later. Luego is slightly more colloquial and shorter. Después is often followed by de when you use a gerund or noun (for example después de firmar), but in this sentence luego smoothly links the two clauses.

What does citar mean in this context, and can I use mencionar instead?

Here citar means to quote or to refer to something as an example. Mencionar means to mention in a more general sense. You could say lo mencionará como ejemplo, but citar emphasizes a formal or exact reference.

What is the role of como ejemplo?

Como ejemplo means as an example. Como indicates the role or function (similar to as in English) and ejemplo is the noun example.

Why is en la conferencia used, and why the article la?

En means in or at a place or event, so en la conferencia translates to at the conference. The definite article la specifies that you’re talking about a particular conference known to both speaker and listener.

Why don’t we attach the pronoun (for example firmarálo or citarálo) instead of placing it before the verb?

In simple tenses like the future, clitic pronouns go before the conjugated verb (proclisis), so you say lo citará rather than citarálo. Enclisis (attaching the pronoun) is only allowed with infinitives, gerunds and affirmative imperatives (for example firmarlo, citarlo, ¡Fírmalos!).