Learn Icelandic: Bíllinn er hér en bókin er þar. - The car is here but the book is there.

Er is the form of the verb vera (to be) used for "he", "she", and "it" (hann, hún, það). Since both "the car" and "the book" are third-person subjects, they both use er just like "it" would.

Where is the word for "the" in this sentence?

In Icelandic, there is usually no separate word for "the". Instead, it gets attached to the end of the noun. So bíll (a car) becomes bíllinn (the car), and bók (a book) becomes bókin (the book).

Why does "the car" end in -inn but "the book" ends in -in?

This happens because Icelandic nouns have grammatical genders, which changes how endings look. Bíll is a masculine noun, so its attached "the" ending is -inn. Bók is a feminine noun, so its ending is -in.

Is en the word for "and"?

No, en means "but" in this sentence. It is easy to confuse with English "and", but if you wanted to say "and" in Icelandic, you would use the word og.