Learn the meanings for “too”.
The first meaning is “also” or “besides”;
The second meaning is “excessively” or “extra”.
In addition, some people use it to mean “very”. Think of too as being relevant when there is an increase in something, such as temperature, difficulty, sensitivity, etc., “too hot”, “too challenging”, or “too soft”. Hence:
Choose the word “too” when it can be substituted for the word “also”.
For example: “She felt awful, too (also)” or “I can see you too (also)”.
Use “too” to modify or emphasize a word.
For example: “The weather is too (excessively) hot”, “I’ve eaten too (excessively) much”, or “The package is too (excessively/extra) big”.
“He wasn’t too (very) interested in my book.”
