"He hates when people are late."<br/><br/>"He hates <b><span style="color:#ff0000;">it</span></b> when people are late."<br/><br/>"He likes when people are on time."<br/><br/>"He likes <b><span style="color:#ff0000;">it</span></b> when people are on time."<br/><br/>How necessary is "it"?