Learn Italian: Questo alluminio, lo possiamo riutilizzare.

In Italian, when you move the object of a sentence to the very beginning to emphasize it (a structure called left dislocation), you must use a pronoun to refer back to it. Questo alluminio is the object, so we use the masculine singular pronoun lo right before the verb to tie it all together.

Can I just leave out the lo like we often do in English when saying 'This aluminum we can reuse'?

No, you cannot drop it. While English often skips the pronoun in this type of phrasing, Italian strictly requires this matching pronoun (lo) whenever the object is pulled to the front for emphasis. Without it, the sentence feels grammatically incomplete to a native speaker.

Could I attach lo to the end of riutilizzare instead of putting it before possiamo?

Yes, absolutely! Because you are using a modal verb (potere) followed by an infinitive (riutilizzare), you have a choice. You can place the pronoun before the conjugated verb (lo possiamo riutilizzare) or attach it to the end of the infinitive by dropping its final -e (possiamo riutilizzarlo). Both are perfectly correct.

How do I know Questo alluminio isn't the subject of the sentence since it comes first?