I would like to ask a question about the future in the past and the adverbial clause used in the sentence which indicates the future.
I know we can indicate future in the past, for example by using "would" or "might" like in the sentences "John said that he would take the examination next year." or "Peter said that he might come tomorrow."
If an adverbial clause is added in the sentences, how can we construct correct sentences?
"John said that he would take the examination before he [entered/would enter?] the university next year." "Peter said that he might come if he [had done?] his homework tomorrow."
Although my textbook says that tenses in subordinate clauses should be usually the same as the tense in the main clause, the adverbial clauses in the above sentences indicate events in the future and I feel it seems strange to use the past tense to indicate the future event.
How can you say in that case?