From what I understand so far here and other resources, "강아지 " in this lesson is a word for a baby dog or a young dog, not older or adult dogs like " 강아지 ".
Otherwise, I can understand why we might think about "dog" as a choice.
In a way, it is a great sentence of contrast and extremes with memory triggers: puppy, speeaking, language, difficult.
I asked this before too. In English there is a distinction in using the present simple and the present continuous. The first indicates a habit (I brush my teeth (every day)), the second indicates the action you are doing right now (I am brushing my teeth (as we speak)). In Korean they do not make this distinction.