… below. You can view a complete listing of Dr. Hartshorne's publications on Google Scholar or in his CV. A critical period for second language acquisition: … Pushkin. Psych verbs, the linking problem, and the acquisition of language. See Google Scholar Profile In addition, Dr. Hartshorne regularly presents at … below. You can view a complete listing of Dr. Hartshorne's publications on Google Scholar or in his CV. A critical period for second language acquisition: …