Alright, let's talk about pronounnciation. Is it important? Absolutely! What most english learners don't know is that not pronouncing certain consonants such as ''th'' may change the whole meaning of a word. Before I get in to it, let's listen to this video.

Sound familiar? Or foreign? Most of our peers aren't able to produce the ''th'' sound when saying ''three'' due to fact that we are not familiar with that consonant. You probably heard ''chree'' instead of''three'' a lot of the times but figured it out because you knew the subject before hand.
Here is video that I wish I had come up with, it is very helpfull and absolutely way easier to understand;