The words 'threw' and 'through' are both pronounced /θru/. 'Threw' is phonetic, 'through' is not.

The word 'sale' and 'sail' are pronounced the same and follow common 'long a' phonetic/spelling patterns: /sɑɪl/.

Here are sets of words with the same pronunciation and the 'ee/ea' spellings. (Don't forget, the 'ea' spelling can have a 'long e' /i/ pronunciation.)