Correct spelling, explanation: the verb show is irregular, which means it doesn’t follow the typical pattern of adding -ed for both the past tense and past participle. It has three key forms: show (the base form), showed (the simple past tense), and shown (the past participle). The form showned is incorrect and does not exist in English. Verbs typically don’t double up their past tense forms, so adding -ed to shown is unnecessary and grammatically wrong. Instead, remember to use showed without auxiliary verbs and shown with helping verbs.

Definition of shown:
Verb (past participle), allow or cause (something) to be visible
The teacher has shown us how to solve the equation step by step.
The data analysis has shown promising results for the new marketing strategy.

Collocations with shown:
Some of the most commonly used collocations include:
1. To have shown interest (in): to demonstrate curiosity or enthusiasm about something.
She has shown great interest in learning foreign languages.
2. To have shown potential: to demonstrate the possibility of future success or growth.
The new employee has shown potential to become a team leader.
3. To have shown results: to display evidence of effectiveness or success.
The new training program has already shown positive results.
4. To have shown support (for): to express encouragement or backing for a person, idea, or cause.
The community has shown tremendous support for the charity event.

Incorrect spelling, explanation: the form showned is a mistake because it doesn’t follow the correct grammatical rules for forming past tense and past participles in English. Show is an irregular verb with the past tense showed and the past participle shown. Unlike regular verbs that add -ed to form both past tense and past participle (like play becoming played), irregular verbs often have distinct forms. English does not typically allow double past-tense forms. The past participle shown already serves its purpose, so adding another -ed (creating showned) is redundant and incorrect.