hey guys quick question....reading and studying around I see sometimes that people use same verbs but with different vowels...changing dammah with fatha or kasrah and viceversa...but the roots still the same....so is that normal and not important as long as the root still the same? (i.e. qibil - qabil, nazal - nizil: qadar , qidir just to say a few of). Thank you

Such a useful video! Thank you :)