( ( ( The ( most ( common problem ) ) ) ( ( ( ( my students ) and ) I ) ( have encountered ) ) ) ( ( ( is unequally ) ( ( sized elements ) ( in ( adjoining cells ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (RBS most) (JJ common) (NN problem)) (SBAR (S (NP (NP (PRP$ my) (NNS students)) (CC and) (NP (PRP I))) (VP (VBP have) (VP (VBN encountered)))))) (VP (VBZ is) (ADVP (RB unequally)) (NP (NP (JJ sized) (NNS elements)) (PP (IN in) (NP (JJ adjoining) (NNS cells))))) (. .)))
The most common problem my students and I have encountered is unequally sized elements in adjoining cells.
(ROOT (S (NP (DT All) (NNS cells)) (VP (VBP have) (NP (NP (DT the) (JJ small) (NN size)) (PP (IN in) (NP (JJ common))))) (. .)))