Compound words and collocations are both types of word combinations, but they differ in their formation and meaning.
Compound words are formed by combining two or more individual words to create a new word with a distinct meaning. These words are typically written as a single unit without any spaces or hyphens. For example, the compound word "sunflower" is formed by combining the words "sun" and "flower." The meaning of the compound word is not directly related to the meanings of the individual words.
On the other hand, collocations are combinations of words that are frequently used together due to common usage and convention. These word combinations are formed based on the natural way that words are used together in a language. Collocations can be fixed or flexible. Fixed collocations are combinations of words that are rigid and cannot be changed, such as "take a ******" or "make a decision." Flexible collocations, on the other hand, are more loosely connected and allow for some variation, such as "strong coffee" or "fast car."
To illustrate the difference, let's take the example of the word "hot chocolate." "Hot chocolate" is a compound word because it is formed by combining the adjective "hot" and the noun "chocolate." The resulting compound word refers specifically to a warm beverage made by mixing chocolate with hot milk or water. On the other hand, the collocation "strong coffee" is not a compound word, but rather a combination of two words that frequently occur together. It refers to a cup of coffee that is brewed with a higher concentration of coffee grounds, resulting in a more intense flavor.
In summary, compound words are formed by combining individual words to create a new word with a distinct meaning, while collocations are natural combinations of words that are commonly used together due to language convention.