To answer your question, we must translate the phrase. Let's begin... The word "Praise" in Spanish is "Alaba". And "The Lord" is "El Señor". So, here we have the phrase " Praise the Lord" in Spanish which is "Alaba El Señor".
If that's " Is it incorrect to say 'praise the lord' as a response to 'praise the lord'?", then since simply saying those words isn't praising the lord (?) but simply sending on a prompt to do. In...
Padre nuestro que estás en el cielo, santificado sea Tu nombre, hágase tu voluntad así en la tierra como en el cielo. Danos hoy nuestro pan de cada día, perdona nuestras ofensas, así como...
Ella fué a estar con el Señor. (Notice the S in Señor is capitalized. If Señor isn't capitalized then it would translate back to "She went to be with the man")