Undeclared variable in just one function - c

Question

So I have a struct that I'm declaring in a function and whenever I try running the program it says that the variable is undeclared. However, that error only appears in that function and it doesn't appear in any other function when I declare that struct.
https://repl.it/#JeevenMann/RelevantWetInverse#main.c
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
typedef struct wordStruct {
char *charPointer;
int numChars;
int wordPos;
struct wordStruct *nextWord;
} word;
typedef struct sentenceStruct{
word *wordObj;
int lineNum;
int wordCount;
struct sentenceStruct *nextSentence;
} sentence;
typedef struct linkedStructure {
sentence *firstSentence;
int sentenceNum;
} LIST;
void printOut(LIST * sentenceList) {
//Declare variables for sentenceIndex
int sentenceIndex = 0;
//reset sentence Index and print out all words on each line
sentenceIndex = 0;
sentence *currentSentence = sentenceList->firstSentence;
printf("\n\nThis is all the words printed out on the same line as entered:\n");
while (currentSentence != NULL) {
word *currentWord = currentSentence->wordObj;
int wordIndex = 0;
while (currentWord != NULL) {
printf("%s ", currentWord->charPointer);
currentWord = currentWord->nextWord;
}
printf("\n");
currentSentence = currentSentence->nextSentence;
}
}
void storeWords(sentence * sentenceObj, char line[]) {
//Declare count variables and index variables
int index = 0;
int wordCount = 1;
int charCount = 1;
word* currentWord;
char copyWord[1000];
//Delegate memory to wordObject and char array
sentenceObj -> wordObj = (word * ) malloc(sizeof(word));
currentWord = sentenceObj->wordObj;
// Loop though sentence until we reach EOS char
while (line[index] != '\n') {
//check if array index is not a space
if (line[index] != ' ') {
//set char to current index
//increase char count
//realloc more memory to char pointers
copyWord[charCount - 1] = line[index];
charCount++;
//if the next index is a EOS symbol or an empty space
if (line[index + 1] == '\n' || line[index + 1] == ' ') {
sentenceObj -> wordCount = wordCount;
currentWord->numChars = charCount - 1;
currentWord->wordPos = wordCount;
copyWord[charCount-1] = '\0';
currentWord->charPointer = (char * ) malloc(sizeof(char) * charCount);
strcpy(currentWord->charPointer,copyWord);
if (line[index + 1] == ' ') {
wordCount++;
charCount = 1;
currentWord->nextWord = (word * ) malloc(sizeof(word));
currentWord = currentWord->nextWord;
currentWord->nextWord = NULL;
strcpy(copyWord,"");
}
}
}
index++;
}
}
LIST * readInput() {
//declare variables for str and lineNum
char str[1000] = "";
int lineNum = 1;
LIST *sentenceList = (LIST *) calloc(1,sizeof(LIST));
sentence *currentSentence;
sentenceList->firstSentence = (sentence * ) calloc(1, sizeof(sentence));
currentSentence = sentenceList->firstSentence;
//while the user doesn't enter an empty string, continue
printf("Enter a string: ");
fgets(str,sizeof(str),stdin);
printf("%s\n",str );
while (strcmp(str, "\n") != 0){
//user hasn't entered an empty string so allocate more memory and populate
//the struct
currentSentence->lineNum = lineNum;
storeWords(currentSentence, str);
lineNum = lineNum + 1;
printf("Enter a string: ");
fgets(str,sizeof(str),stdin);
printf("%s\n",str );
if (strcmp(str, "\n") != 0) {
currentSentence->nextSentence = (sentence * ) calloc(1, sizeof(sentence));
currentSentence = currentSentence->nextSentence;
currentSentence->nextSentence = NULL;
}
}
//print out the sentence as defined by assignment
printOut(sentenceList);
return sentenceList;
}
int searchSentences(LIST * sentenceList, char word[]) {
//Declare variables for the sentence index and return int boolean if word is found
int sentenceIndex = 0;
int wordFound = 0;
//loop through sentenceObjects and print out if that word matches word to find
sentence *currentSentence = sentenceList->firstSentence;
printf("\n\nThis is all the words printed out on the same line as entered:\n");
while (currentSentence != NULL) {
word *theWord = currentSentence->wordObj;
int wordIndex = 0;
while (theWord != NULL) {
if (strcmp(theWord->charPointer,word) == 0) {
printf("%s found in line %d position %d\n", word, currentSentence->lineNum, theWord.wordPos);
wordFound = 1;
}
theWord = theWord->nextWord;
}
printf("\n");
currentSentence = currentSentence->nextSentence;
}
return wordFound;
}
void findString(LIST * sentenceList) {
//declare char array
char str[1000];
//while the user doesn't enter an empty string continue to search for the word
do {
printf("\n\nEnter a word to search for:\n");
fgets(str,sizeof(str),stdin);
str[strlen(str)-1] = '\0';
if (strcmp(str, "") != 0 && searchSentences(sentenceList, str) == 0) {
printf("%s was not found in this file\n", str);
}
} while (strcmp(str, "") != 0);
}
int main() {
//Declare line objects
LIST *sentenceList;
//get Number of lines and ask user for info
sentenceList = readInput();
findString(sentenceList);
return 0;
}
Thanks, I've been trying to fix this for a while now, but I can't seem to figure out why it's not working.