$(S NP+VP NP Det N VP Vb+NP Vb Aux+V Det {the,a,this,that... N {table,girl,boy,letter,undergraduate ... Aux {will,can,might,should,be ... V {post,repair,buy,teach,sit...} 台MV {main verb}) (next) 4 (S NP+VP NP Det + N VP Vb+NP Vb Aux+V Det {the, a, this, that …} N {table, girl, boy, letter, undergraduate …} Aux {will, can, might, should, be …} V {post, repair, buy, teach, sit …} MV {main verb} ) （next）