Here are a few possibilities:
1. Suffixes: These are letters or groups of letters that are added to the end of a base word to change its meaning or grammatical function. For example:
* Base word: "happy"
* Suffix: "-ness"
* New word: "happiness"
2. Prefixes: These are letters or groups of letters that are added to the beginning of a base word to change its meaning. For example:
* Base word: "happy"
* Prefix: "un-"
* New word: "unhappy"
3. Other words: A base word can be followed by other words to form a phrase or sentence.
* Base word: "run"
* Other words: "quickly," "around the block," "to the store"
4. Endings: In some cases, a base word might be followed by a specific ending, such as a question mark or an exclamation mark.
* Base word: "hello"
* Ending: "?"
* New word: "hello?"
To give you a more precise answer, please tell me:
* What kind of word are you thinking of? (noun, verb, adjective, etc.)
* What are you trying to do with the base word? (change its meaning, make it plural, etc.)
Let me know, and I can help you further!