Should text in button be capitalized in English? [duplicate]

Yes, capitalizing the Initials for every new word for the button's text makes it more legitimate to click and improves the harmony of the entire UI. If you are having trouble in cutting down your Button's Text to 2-3 words, it's probably time you should use an icon instead to depict the action clearly.

1. Should words in buttons be capitalized?
2. Should CTA buttons be sentence case?
3. Should English muffin be capitalized?

Should words in buttons be capitalized?

Capitalize the first word of a sentence, heading, title, UI label (such as the name of a button or checkbox), or standalone phrase. Capitalize proper nouns. To learn more about proper nouns, see Nouns and pronouns. Use lowercase for everything else.

Should CTA buttons be sentence case?

Using the Title Case should be limited to writing titles, for CTA's (Call To Action) (<-Look, Title Case), you should use Sentence case because that lowers the cognitive load of reading the text.

Should English muffin be capitalized?

The same rule applies to any adjectives that are derived from a proper noun. I ate two English muffins for breakfast. However, you don't need to capitalize generic terms. For example, "lake" by itself would be lowercase, but "Lake Louise" must be capitalized.