DONDE
The relative pronoun donde is used to refer to talk about places or locations.Vamos a pasear por el parque donde hay unos jardines y lagos muy bonitos.
We are going to walk around the park where there are some very beautiful gardens and ponds.
Recogeré a Javier donde le dejé esta tarde.
I'll pick up Javier where I dropped him off this afternoon.
With verbs that express movement such as "ir a", "viajar a", donde is usually replaced for adonde with no change in meaning. Iré adonde (donde) tú quieras ir.
I'll go wherever you want to go.
Viajaremos hasta adonde (donde) nos llegue la gasolina.
We will travel wherever until we run out of gas.
CUANTO, CUANTA, CUANTOS, CUANTAS
The relative pronouns cuanto, cuanta, cuantos, cuantas are not commonly used in the spoken language anymore and they even sound old-fashioned in the written language. Instead, they are substituted for todo lo que/toda la que/todos los que/todas las que. The pronouns lo/la/los/las can be replaced for the subject of the sentence. They are used to express quantity.Inflaremos cuantos globos (todos los globos que) sean necesarios para la fiesta.
We'll inflate as many balloons as we need for the party.
Le prestaré cuanto dinero (todo el dinero que) necesite.
I'll lend him as much money as he needs.