How to pronounce the?

1. Textbooks, dictionaries, church, theaters: [ðə] + C, [ði] + V

2.  In AmE, the distinction is not observed: [ðə] + C/V

3.  If 'the' not stressed,  [ə] + C

4.  [ð] + V in conversational tempos

     [ðɪ] + most vowels in slow tempos

     [ði] + /ɪ/ in slow tempos
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the + V:
1. [ði]
2. [ðɪ]
3. [ði] before /ɪ/
4. [ð] 


the + C:
1.[ðə]
2. [ə]  cf: all the; in the; on the


EPT, CJB, p. 189-90
ETBLA, CJB, p 295