When 3- and 4-year-olds use their newfound capacity to talk about mental states during play with friends, their understanding of false belief improves further.
( ( When ( ( ( ( 3 - ) and ) 4-year-olds ) ( ( use ( their ( newfound capacity ) ) ) ( to ( ( talk ( about ( mental states ) ) ) ( during ( play ( with friends ) ) ) ) ) ) ) ) ( , ( ( ( their understanding ) ( of ( false belief ) ) ) ( ( improves further ) . ) ) ) )
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NP (CD 3)) (: -) (CC and) (NP (JJ 4-year-olds))) (VP (VBP use) (NP (PRP$ their) (JJ newfound) (NN capacity)) (S (VP (TO to) (VP (VB talk) (PP (IN about) (NP (JJ mental) (NNS states))) (PP (IN during) (NP (NP (NN play)) (PP (IN with) (NP (NNS friends))))))))))) (, ,) (NP (NP (PRP$ their) (NN understanding)) (PP (IN of) (NP (JJ false) (NN belief)))) (VP (VBZ improves) (ADVP (RBR further))) (. .)))
Children have the ability to understand false belief.
( Children ( ( have ( the ( ability ( to ( understand ( false belief ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Children)) (VP (VBP have) (NP (DT the) (NN ability) (S (VP (TO to) (VP (VB understand) (NP (JJ false) (NN belief))))))) (. .)))