"But also what is missing" is not a complete thought, which tells us that your sentence is not correctly fixed when you take both of the other commas. You only have one sentence and two dependent clauses. The basic sentence is "The child will not only remember what comes next, but also what is missing." The word "By" at the start indicates a dependent claus, so you were right to have that comma after 'feet.' You don't need to separate the two verbs that are both in play together (By using and beginning...,).
Edit: By using order and beginning at the child's head [and] working...down to the feet, the child will not only remember what comes next, but also what is missing.
"But also what is missing" is not a complete thought, which tells us that your sentence is not correctly fixed when you take both of the other commas. You only have one sentence and two dependent clauses. The basic sentence is "The child will not only remember what comes next, but also what is missing." The word "By" at the start indicates a dependent claus, so you were right to have that comma after 'feet.' You don't need to separate the two verbs that are both in play together (By using and beginning...,).
ReplyDeleteEdit:
By using order and beginning at the child's head [and] working...down to the feet, the child will not only remember what comes next, but also what is missing.