a word part that cannot stand alone. It is placed at the beginning of a word to change its meaning.

The word part that fits the given description is a prefix. A prefix is added to the beginning of a word to modify its meaning, but it cannot stand alone as a meaningful word on its own.

The word part you are referring to is called a prefix. A prefix is a group of letters added to the beginning of a base word to change its meaning. It cannot stand alone as a complete word but only modifies the meaning of the word it is attached to.

The word part you are referring to is called a "prefix." A prefix is a linguistic element that is attached to the beginning of a word to modify its meaning. It cannot stand alone as a complete word but needs to be combined with a base word to form a complete word.

To determine the meaning of a word with a prefix, you can approach it by breaking it down into its constituent parts. First, identify the prefix and separate it from the rest of the word. Then, examine the meaning of the base word, which is the word without the prefix. Finally, combine the meaning of the prefix with the base word to understand the complete meaning of the word.

For example, let's consider the word "preheat." The prefix in this word is "pre-," and the base word is "heat." The prefix "pre-" means "before" or "prior to." The base word "heat" refers to the process of making something hot. Therefore, when you combine the prefix and the base word, "preheat" means to heat something before the usual or expected time.