When two vocal shewas appear consecutively
When two vocal shewas appear consecutively, the first shewa is pressed into the full short vowel.
If they are both simple vocal shewas, the first shewa becomes a hirek. לִפְרִי, כִּבְרִית
If the second shewa is a compound shewa, the first shewa will be pressed into the shortest full vowel of the same class as the compound shewa. בָּֽחֳלִי, לֶאֱלֹהִים, כַּאֲשֶׁר.