pdo if statments are not working when checking the value - php

Question

This is a code that I designed to check if username matches with the email in the database.
If not check the username. if it does not exist, check the email. If it does not exist, create a new username.
The problem is that the query runs and insert a new user every time!! What am I doing wrong??
$word = $_POST['word'];
$explination = $_POST['explination'];
$lhgat = $_POST['lhgat'];
$email = $_POST['email'];
$username = $_POST['username'];
$letterar = idar($_POST['word']);
$letteren = iden($_POST['word']);
if (!empty($word) && !empty($explination) && !empty($lhgat) && !empty($email) && !empty($username) && !empty($letterar) && !empty($letteren)) {
//checking for username and email match
$checkingforuserstmt = $conn->prepare('SELECT id FROM user WHERE username = username AND email = email');
$checkingforuserstmt->execute(array(':username' => $username, ':email' => $email));
$checkingforuserrow = $checkingforuserstmt->fetch(PDO::FETCH_ASSOC);
if($checkingforuserstmt->rowCount() < 0){
//check for username only
$checkingforuserstmt2 = $conn->prepare('SELECT id FROM user WHERE username = username');
$checkingforuserstmt2->execute(array(':username' => $username));
$checkingforuserrow2 = $checkingforuserstmt2->fetch(PDO::FETCH_ASSOC);
if($checkingforuserrow2->rowCount() < 0){
//check for email only
$checkingforuserstmt3 = $conn->prepare('SELECT id FROM user WHERE email = email');
$checkingforuserstmt3->execute(array(':email' => $email));
$checkingforuserrow3 = $checkingforuserstmt3->fetch(PDO::FETCH_ASSOC);
if($checkingforuserrow3->rowCount() < 0){
$insertuser = $conn->prepare("INSERT INTO user VALUES('',:username,:email)");
$insertuser->execute(array(':username' => $username,':email' => $email)); }}}

Answer 1

You need to use the : in the statement, not the binding. for example: select * from table where field = :field not field = field
Otherwise you're just saying the column, not a value.