This is simple function to add English ordinal number suffix after normal number. Function takes number as a parameter and returns number with suffix, like:
1st, 2nd, 3rd, 4th, 5th, 6th…

This is example table of ordinal numbers 1 to 100

1st	 2nd	 3rd	 4th	 5th	 6th	 7th	 8th	 9th	 10th	
11th	12th	13th	14th	15th	16th	17th	18th	19th	20th	
21st	22nd	23rd	24th	25th	26th	27th	28th	29th	30th	
31st	32nd	33rd	34th	35th	36th	37th	38th	39th	40th	
41st	42nd	43rd	44th	45th	46th	47th	48th	49th	50th	
51st	52nd	53rd	54th	55th	56th	57th	58th	59th	60th	
61st	62nd	63rd	64th	65th	66th	67th	68th	69th	70th	
71st	72nd	73rd	74th	75th	76th	77th	78th	79th	80th	
81st	82nd	83rd	84th	85th	86th	87th	88th	89th	90th	
91st	92nd	93rd	94th	95th	96th	97th	98th	99th	100th

Add Ordinal Suffix PHP Function

<?php

  function addOrdinalNumberSuffix($num) {
    if (!in_array(($num % 100),array(11,12,13))){
      switch ($num % 10) {
        // Handle 1st, 2nd, 3rd
        case 1:  return $num.'st';
        case 2:  return $num.'nd';
        case 3:  return $num.'rd';
      }
    }
    return $num.'th';
  }

Add Ordinal Suffix PHP Function Usage/Testing

for ($i = 1; $i <= 10000; $i++){
  echo addOrdinalNumberSuffix($i) . "\t";
  if ($i % 10 == 0) {
    echo "\n";
  }
} 

Output:

1st	2nd	3rd	4th	5th	6th	7th	8th	9th	10th	
11th	12th	13th	14th	15th	16th	17th	18th	19th	20th	
21st	22nd	23rd	24th	25th	26th	27th	28th	29th	30th	
31st	32nd	33rd	34th	35th	36th	37th	38th	39th	40th	
41st	42nd	43rd	44th	45th	46th	47th	48th	49th	50th	
51st	52nd	53rd	54th	55th	56th	57th	58th	59th	60th	
61st	62nd	63rd	64th	65th	66th	67th	68th	69th	70th	
71st	72nd	73rd	74th	75th	76th	77th	78th	79th	80th	
81st	82nd	83rd	84th	85th	86th	87th	88th	89th	90th	
91st	92nd	93rd	94th	95th	96th	97th	98th	99th	100th	
101st	102nd	103rd	104th	105th	106th	107th	108th	109th	110th
...
9961st	9962nd	9963rd	9964th	9965th	9966th	9967th	9968th	9969th	9970th	
9971st	9972nd	9973rd	9974th	9975th	9976th	9977th	9978th	9979th	9980th	
9981st	9982nd	9983rd	9984th	9985th	9986th	9987th	9988th	9989th	9990th	
9991st	9992nd	9993rd	9994th	9995th	9996th	9997th	9998th	9999th	10000th