1.
Read the music written for an oboe.
2.
Transpose by lifting each note seven half steps. Think of half-steps as the black keys on a piano. Each white key is a note that is different from the next white key while a black key is half the tone.
3.
Write about the music with the raised notes. Because the English horn produces sounds lower than those written, by writing the music louder, you will interrupt the lowering effect.
4.
Remember the chromatic waves so that you won ‘t cause mistakes to be incorporated. No such note as a Cb (C flat) exists because the next step down is a full step to a B. Follow the keys on a piano for help.
5.
Memorize the new places. After memorization, you should be able to transfer music while playing.
Tips and warnings
The hobby and the English horn are similar but still have their differences. Both are uniform, but differ in length; and both use double reeds, but differ in sound. They really differ in the gameplay. The hobby is a concert instrument, playing a C when a C is noted in the music. However, the English horn is a perfect fifth below it, which means that a C on the music would actually create a resonant height of a G octave below. Transposition then comes in handy.
Source:danspela.com