( ( Although ( ( sea otters ) ( can ( be ( ( playful and ) sociable ) ) ) ) ) ( , ( they ( ( ( are not ) ( considered ( to ( be ( ( truly social ) animals ) ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN Although) (S (NP (NN sea) (NNS otters)) (VP (MD can) (VP (VB be) (ADJP (JJ playful) (CC and) (JJ sociable)))))) (, ,) (NP (PRP they)) (VP (VBP are) (RB not) (VP (VBN considered) (S (VP (TO to) (VP (VB be) (NP (ADJP (RB truly) (JJ social)) (NNS animals))))))) (. .)))
Although sea otters can be playful and sociable, they are not considered to be truly social animals.
(ROOT (S (NP (NNP Sea) (NNS otters)) (VP (VBP are) (VP (VBN known) (PP (IN for) (S (VP (VBG being) (ADJP (JJ playful) (CC and) (JJ frisky))))))) (. .)))