* Comparative Adjective: This is the most common use. It adds the meaning of "more" or "to a greater extent" to an adjective. Examples:
* big + -er = bigger
* tall + -er = taller
* fast + -er = faster
* Agent Noun (person or thing that performs an action): This suffix indicates the person or thing that does something. Examples:
* teach + -er = teacher
* sing + -er = singer
* work + -er = worker
* play + -er = player
* Instrument or device: Less common than the above, but it can indicate a tool or device that performs a specific action. Example:
* chop + -er = chopper (a tool for chopping)
It's important to note that some words don't follow the standard rules, particularly with one-syllable adjectives ending in a single vowel followed by a single consonant (like "big"). These often double the consonant before adding "-er" (bigger). Also, some words are irregular and don't follow these patterns at all.
In short, while the core meaning hinges on comparison or agency, the specific nuance of "-er" depends heavily on the root word it's attached to.