Оканчивать (Imperfective aspect) // Окончить (Perfective aspect)
to graduate from,
to complete,
to finish.
Imperfective verbs have Present, Past and Future tenses.
Perfective verbs have Past and Future tenses.
PDF-file with all the forms in the sentences is available here - www.patreon.com/rulangclub/ and https://boosty.to/rulangclub.