#include <string.h>
 
int main(void)
{
    char *str = "aardwolf  it is animal";
    char *p = str, *wrdbeg;
 
    str = strchr(str, 'a');
 
    if (str)
    {
        while (str)
        {
            wrdbeg = str;
            while ( ( wrdbeg != p ) && ( *(wrdbeg - 1) != ' ') )
                --wrdbeg;
            while( ( *str != 0 ) && ( *(str + 1) != ' ') )
                ++str;
            while ( wrdbeg != str )
                putchar( *( wrdbeg++ ) );
            putchar('\n');
            str = strchr(str, 'a');
        }
    }
    else
        puts("symbol 'a' is not found");
 
    return 0;
}

aardwol
animal