להבדיל

As I have discussed in a different forum, the essence of פרשת שמיני is one word - להבדיל, do differentiate. Towards the end of the פרשה, in פרק י"א that manifests itself in a דקדוק sense as well. There are two sets of words which appear very similar but must be pronounced differently so that they take on their proper meaning:

1)

לד  מִכָּל־הָאֹ֜כֶל אֲשֶׁ֣ר יֵאָכֵ֗ל 

Here, אכל means food items.  

מ  וְהָֽאֹכֵל֙ מִנִּבְלָתָ֔הּ

Here, אכל refers to a person who eats.

The trop is included to stress the difference in accent. The first is pronounced with a סגול and מלעיל. The second is with a צירי and מלרע.

2)

מג וְלֹא תִטַּמְּאוּ is with a חיריק meaning "do not become טמא," whereas
מד וְלֹא תְטַמְּאוּ is with a שוא meaning "do not make טמא."

Both are definitely correctable. I once heard someone get the vowel right but the accent wrong on #1 (or vice versa, can't remember) and I corrected it on the spot.