Why "heared" is incorrect: a detailed explanation

What kind of error is it?

This is an irregular verb conjugation error.

Why do people make this mistake?

People often make this error because in English, many verbs form their past tense by adding "-ed" to the base form. This pattern can lead to the incorrect assumption that "hear" follows the same rule.

What is correct?

The correct spelling for the past tense of "to hear" is "heard". It's pronounced /hɜːrd/, rhyming with "bird" and "word".