Complex sentence: The Think Before You Speak campaign is a television, radio, and magazine advertising campaign developed to raise awareness of the common use of anti-LGBT vocabulary among youth, created by the Arnold Agency and the Gay, Lesbian and Straight Education Network (GLSEN).
Split into simpler sentences: The Think Before You Speak campaign is a television, radio, and magazine advertising campaign developed to raise awareness of the common use of derogatory vocabulary among youth towards lesbian, gay, bisexual, transgender, queer/questioning (LGBTQ) people. The campaign was created by the Arnold Agency and the Gay, Lesbian and Straight Education Network (GLSEN).