find a specific word in a string and add another string after that specific word php code example

Example 1: php check if string contains word

$myString = 'Hello Bob how are you?';
if (strpos($myString, 'Bob') !== false) {
    echo "My string contains Bob";
}

Example 2: contains php

if (strpos($a, 'are') !== false) {
    echo 'true';
}