2b HA
Present Perfect vs Past Simple:
https://www.english-4u.de/en/tenses-exercises/perfect-past-simple.htm
https://www.english-4u.de/en/tenses-exercises/perfect-past-simple2.htm
https://www.english-4u.de/en/tenses-exercises/perfect-past-simple3.htm
https://www.english-4u.de/en/tenses-exercises/perfect-past-simple4.htm
https://www.english-4u.de/en/tenses-exercises/past-simple-perfect.htm
https://www.english-4u.de/en/tenses-exercises/perfect-past-tenses.htm
https://www.englishpage.com/verbpage/verbs5.htm
https://www.english-practice.at/b1/grammar/tenses/t-036-past-present-perfect-simple.pdf
https://www.english-practice.at/b1/grammar/tenses/t-027-past-present-perfect-simple.pdf