Los billetes del tren

Question

¿Tienes tú los billetes del tren?I answered 'si, tengo' but it was marked incorrect and should have been' si, los tengo'.   Would you explain please? Many thanks.

Answer

Hola Trefor
This example is one that is including a determiner "los" in front of the object. The last part of the lesson is pointing at these cases where you do need to include the pronoun if the object is made "more specific", like in this case. We have another sentence in the lesson that uses a definite article:
-¿Llevas la maleta azul en el maletero? -No, no la llevo.
-Do you have the blue bag in the boot? -No, I don't (have it).
I hope this clarified it.
Saludos

Answer

Many thanks, Inma.