1. Excessive or more than necessary:
* Example: The cake was too sweet.
* Meaning: The cake had an excessive amount of sweetness, more than what was desirable.
2. Also or in addition:
* Example: I like pizza, and my friend likes pizza too.
* Meaning: Both the speaker and their friend share the same liking for pizza.
3. Very:
* Example: I'm too tired to go out tonight.
* Meaning: The speaker is extremely tired and unable to go out.
4. (Archaic) Before:
* Example: Too late, he realized his mistake.
* Meaning: Before it was too late, he realized his mistake. This usage is now uncommon.
It's important to look at the context of the sentence to understand which meaning of "too" is intended.