It's and its are two different words: the first is a contraction of "it is," and the second is the possessive form, "of it." It's okay, the river hasn't risen over its banks = it is okay, the river...
If you have a word processing program such as Microsoft Word you can type a word onto a page and then spell check the word.
Or even on a program like this one for answering your question when I...
Pachacuti, also spelled Pachacútec and Pachakutiq means "He who remakes the world" and is the name of the Inca king who began an era of conquest that, within three generations, expanded the Inca...