The ability to understand speakers' intentions is examined for typically developing children (TDC), children with autism spectrum disorders (ASD), and children with attention deficit/hyperactivity disorder (ADHD). Four types of spoken phrases, expressing praise, sarcasm, blame, and banter, were presented, and subjects were asked to judge if the speaker praises you or not, or if she blames you or not. The children could correctly judge the speaker's intention for congruent phrases such as praise and blame. TDC younger than 8 years had significantly lower correct percent compared to the TDC older than them for the sarcastic and banter phrases, which have incongruent linguistic and affective valences. The correct percent was significantly lower for ASD aged 10 years compared to the age-matched TDC and ADHD groups.