Learn Spanish (Latin America): Invito a la familia al restaurante. - I am inviting the family to the restaurant.

This is called the personal a. In Spanish, when the direct receiver of an action is a specific person, a pet, or a group of people (like la familia), you must put the word a right before it. It doesn't translate to anything in English; it is just a required grammar rule!

Why does it say al restaurante instead of a el restaurante?

In Spanish, whenever the preposition a (to) comes right before the masculine article el (the), they always combine to form the contraction al. You will never see a el written as two separate words!

The translation says 'I am inviting', but isn't invito just 'I invite'?

Yes, invito is the simple present tense. However, in Spanish, the simple present can mean both 'I invite' (a general habit) and 'I am inviting' (something happening right now). You don't always need a continuous tense to express an action happening in the moment like you do in English.

Why isn't the word for 'I' (yo) used at the beginning of the sentence?

Because Spanish verb endings change depending on who is doing the action, the subject pronoun is often dropped. The -o ending on invito already tells us that 'I' (yo) am the one doing the inviting, so adding the pronoun is completely optional and usually left out.