Fractions

Unfortunately for those of us learning the language, there's more than one way to express fractions in Spanish. For example, to say "one-third," you can use una tercera parte or un tercio. For a twentieth, it's veintavo (or veinteavo). And for most fractions, to use "one-eleventh" as an example, there's another form: undécimo parte. There are really no hard and fast rules about which form is preferable — sometimes one just "sounds better" to the native ear.