Both Verbs and Adjectives Conjugate
English adjectives usually do not change their form in the same way as verbs. Korean adjectives, however, have stems and combine with endings just as Korean verbs do.
A Common Misconception
Learners may expect a Korean adjective to remain in its dictionary form. Instead, both verbs and adjectives change form when they combine with endings. Their possible endings and functions are not identical in every situation.
The Same Basic Principles Apply
In the regular examples taught here, verbs and adjectives use the same basic principles when forming -아요/-어요 forms. Check the stem's last vowel and then apply any required contraction or deletion.
Examples
먹다 : 먹- + -어요 → 먹어요
예쁘다 : 예쁘- + -어요 → 예뻐요 after ㅡ deletion
작다 : 작- + -아요 → 작아요
Adding Conditions with -(으)면
In the regular patterns taught here, both verbs and adjectives select between -면 and -으면 according to how the stem ends.
Examples
먹다 : 먹- + -으면 → 먹으면
예쁘다 : 예쁘- + -면 → 예쁘면
작다 : 작- + -으면 → 작으면
This shared selection principle does not mean that every verb and adjective has identical behavior with every ending.
Boundary: They Are Not Identical
Verbs and adjectives share many form-building principles, but the same ending does not necessarily have the same function with both types.
Important Difference
먹으세요 can function as a polite instruction meaning "Please eat." 예쁘세요 is also a possible form, but it normally describes someone's state with honorific meaning rather than commanding that person to become pretty.
Therefore, compare both the form and its function instead of assuming that every ending works identically with verbs and adjectives.