Here's why:
* It's a preposition: Prepositions are generally unstressed words.
* It's usually used in phrases: For example, "from the store," "from my friend," "from home." In these phrases, the stress falls on the following noun or pronoun.
* Emphasis: You can stress "from" if you want to emphasize it for special effect, but this is uncommon.
Example:
* "I came from the store." (Unstressed)
* "It was from me, not her." (Stressed, for emphasis)
Let me know if you have any other questions about stress in English!