These rules were not used extensively.
( ( These rules ) ( ( ( were not ) ( used extensively ) ) . ) )
(ROOT (S (NP (DT These) (NNS rules)) (VP (VBD were) (RB not) (VP (VBN used) (ADVP (RB extensively)))) (. .)))
These rules were used often and in high frequency.
( ( These rules ) ( ( were ( used ( ( often and ) ( in ( high frequency ) ) ) ) ) . ) )
(ROOT (S (NP (DT These) (NNS rules)) (VP (VBD were) (VP (VBN used) (UCP (ADVP (RB often)) (CC and) (PP (IN in) (NP (JJ high) (NN frequency)))))) (. .)))