Simplify the following text for a Grade 6 native English-speaking person.
Original: At the time of Speers ' attempt , Klingon even lacked words for many objects common around the house , such as `` table '' . The experiment ultimately failed when the child refused to use Klingon when he got older .
Simplified: When the child became older , he did not want to learn Klingon any more , because there was nobody to talk in Klingon .