How we speak a language does create an impression. How well we speak the language tells the people that you are speaking to, how well you know that language. Speaking well is positive and should be the goal of the speaker. People who speak poorly in their own language may leave a bad impression with the listener. People who are learning a foreign language are always 'students', so are always in a 'learning process'. Anyone who tries to learn a different language is improving the quality of their lives so can always be admired. When communicating with people in a foriegn language, we sometimes use words that are not correct but are similar. So in communication it is okay, but it is best to try to learn the 'proper' (correct) word especially when in writing that language.

it is not clear; what about giving some examples, please ? === (after your first comment) I would say that is perfectly acceptable even from a native speaker! By the way, do your activities require to speak as well as a native speaker ? === # 3 In this case be sure that your efforts to be precise will be appreciated and will tell something good about you.

While using the most appropriate word will send a good impression, stalling and stuttering to find the perfect word will not. It is better to sacrifice perfection in order to be understood..