How to change/set/assign parameter's value for an entity query?
There are some nice examples in the comments on the api documention page for Entity queries https://api.drupal.org/api/drupal/core!lib!Drupal.php/function/Drupal%3A%3AentityQuery/8.2.x

One example assigns a value to a variable, then uses the variable in the query:

$value = 'some value';
$query = \Drupal::entityQuery('entity_type');
$query-&gt;condition('field', $value);
$entity_ids = $query-&gt;execute();


In your loop you could re-assign the value as needed before executing the query.

Another example sets up some functions, so that might be an option and then your loop could call the function.

function someFunction($value) {

  $query = \Drupal::entityQuery('entity_type');
  $query-&gt;condition('field', $value);
  $entity_ids = $query-&gt;execute();

}


Or you could clone the part that stays the same in your loop and alter the rest.  Using your code as an example...

$base_query = \Drupal::entityQuery('taxonomy_term'); 
$base_query-&gt;condition('vid', 'some_vocabulary'); 

for ($i = 1; $i &lt;= 10; $i++) { 
  $query = clone $base_query;
  $query-&gt;condition('tid', $tids[$i]); 
  $query-&gt;execute(); 
  //...
}