The auto correction feature is part of the virtual keyboard application you use and will vary from app to app. All Android phones come with manufacturer designed keyboards (some also come with Swype pre-installed) and users can install third party solutions according to their preferences.
If you are using the default (manufacturer’s) keyboard and wish to switch off the auto correct feature, open up the settings page by pressing the menu key on a home screen and selecting ‘Settings’.
On the settings page, scroll down and look for ‘Language and Keyboards’ or ‘Language and Input’ (settings vary from one version of Android to another). Tap the corresponding option to proceed.
The Language and input screen lists all the input methods enabled on your Android device. These may range from Google voice typing to third party applications like Swiftkey. You can tap any of these to access their settings.
If you are using the default keyboard (Android keyboard for example), tap it to open settings. Newer versions of the keyboards have several options, such as Next word suggestions, Usability study mode and Gesture input. However, look for Auto-correction and select it.
You can choose to either switch off auto correct or choose from modest, aggressive or very aggressive modes. Some keyboards will only have an off or on option for auto correction, while others may have additional options to supplement the auto correct function.