With default settings intact, your iPhone merely requires a single tap of an on-screen button to select an item. If that changes, then you've unwittingly enabled VoiceOver, an accessibility feature on your iPhone. When enabled, your iPhone will speak menu items when you select them and require you to double-tap menus to open items. Disable VoiceOver to get back to business as usual on your iPhone.
Tap "Settings" then double-tap "Settings" from the iPhone's home screen to open the app. Use this method to select menu options.
Video of the Day
Select "General" to view more options.
Select "Accessibility" to view more options.
Select "VoiceOver" to open VoiceOver options.
Select the "On" listing to change VoiceOver to "Off."