(S (S (PP-SBJ (BASENP (NN 少年)) (IN は)) (VP (VP (PP (BASENP (NN 右腕)) (IN で)) (VP (PP-OBJ (NP (PP (BASENP (NN ライフル)) (IN の)) (NN 台尻)) (IN を)) (VBV 持ち))) (COMMA 、) (VP (PP-OBJ (BASENP (NN 指)) (IN を)) (VP (PP (BASENP (NN 引き金)) (IN に)) (VP (VP (VBV かけ) (INTE て)) (VP (VBV い) (VP (MD た)))))))) (PERIOD 。))
少年 は 右腕 で ライフル の 台尻 を 持ち 、 指 を 引き金 に かけ て い た 。
The boy held the rifle at the butt in his right arm with his finger on the trigger .