Hi, Correct me if I am wrong, but I've been taught that you can use an <... ago> phrase in a past tense sentence, as in "I finished the work just a while ago". And, I have also been taught that an <... ago> phrase can't be used in a present perfect sentence. I am still wondering if none of the following sentences are correct. a) I have finished the work just a while ago. b) I have just finished the work a while ago. c) I have just a while ago finished the work. Thank you in advance for your help!