"expected unqualified-id" Error after trying to add delay to parts of script.

I played with the code a little bit (I don't know if I've actually changed anything..) and I still get the same error, also I don't really think I know what you mean by defining an DHT object? Including and using the lib and setting the pin is not enough for proper functioning?

#include <SimpleDHT.h>
#include <LiquidCrystal.h>
#include <Time.h>
#include <Wire.h>
#include <DS1307RTC.h>
#define screen LiquidCrystal
#define sensor SimpleDHT11 

int DHT11_PIN = 2;
unsigned int DHTcheck = 0;
int RSPin = 6;
int EnablePin = 7;
int DS4 = 9;
int DS5 = 10;
int DS6 = 11;
int DS7 = 12;

int LCDColumns = 16;
int LCDRows = 2;
LiquidCrystal screen(RSPin, EnablePin, DS4, DS5, DS6, DS7);
long LastCheck = 0;
const long interval = 1800000;

void setup ()
{
  screen.begin(LCDColumns, LCDRows); //Configure the LCD
  setSyncProvider(RTC.get); //Declare RTC as time data source
}

void loop()
{
  digitalClockDisplay();
  DHTsensor();
}
void digitalClockDisplay () {
  screen.setCursor(0, 0);
  screen.print(hour());
  screen.print(":");
  screen.print(minute());
  screen.setCursor(6, 0);
  screen.print(day());
  screen.print(".");
  screen.print(month());
  screen.print(".");
  screen.print(year());
}

void DHTsensor () {

  unsigned long CurrentTime = millis();

  if (CurrentTime - LastCheck >= interval) {
    LastCheck = CurrentTime;
    DHTcheck = sensor.read11(DHT11_PIN);
  }
  screen.setCursor(0, 1);
  screen.print("H:");
  screen.print(sensor.humidity, 1);
  screen.setCursor(9, 1);
  screen.print("T:");
  screen.print(sensor.temperature, 1);

}