(Play the chords once each on this part.)
Am          E            Am           E
A la nanita nana, nanita ella, nanita ella.
Dm             Am            E            Am
 Mi Nina tiene sueno bendito sea, bendito sea.

(Play flowingly here as opposed to the last time you played this part.)
Am          E            Am           E
A la nanita nana, nanita ella, nanita ella.
Dm            Am            E            A (Play once and let it sound.*)
Mi Nina tiene sueno bendito sea, bendito sea.

(Play the chords once each and let them sound* on this part.)

Note: Stop the chords, with an X after them , where the X is placed.

A                E     (X)
  Fuentecita que corre,
E         A    (X)
Clara y sonora.
A                    E
  Ruisenor que en la sielva,
E        A      (X)
Cantando llora.

Dm                Am
Calla mientras la cuna,
E        Am
Se balansea.
Dm           Am     E      Am
A la nanita nana, nanita ella.

(Play flowingly here as opposed to the last time you played this part.)
A                E
  Fuentecita que corre,
E         A
Clara y sonora.
A                     E
  Ruisenor que en la sielva,
E        A
Cantando llora.

Dm                Am
Calla mientras la cuna,
E        Am
Se balansea.

(Play each of the following chords once and let them sound*)
Dm           Am   E      A
A la nanita nana, nanita ella.

*When i write "Let it (or them ) sound" I mean you play the chord (or chords) once and 
wait 'till it dies out.