As an English teacher, I see all sorts of glorious mistakes when non-native speakers talk. They are glorious because at least people are making an attempt at communication. It can be difficult to be brave and put yourself out there, and some people have the guts to try. Nonetheless, it is useful to discuss the common mistakes that I hear and some ad hoc ways to attempt to correct them.
The first is the mispronunciation of “-ed” at the end of the simple past tense of a verb. The sound often becomes something of an artificial syllable as people attempt to actually use that “e.” This is completely unnecessary. I often abbreviate the words for my students into a form such as “clos’d” and “open’d” simply to emphasize how the word sounds in everyday speech.
The second is the mispronunciation of “th” at the beginning of a sentence. This one has bedeviled native speakers and foreigners for years and years. I had to attend speech therapy (a-ha! see what I did there? Use this paragraph for additional therapeutic and authentic practice when you finish the text at the very end). when I was seven years old just to master this interdental sound. It is amazing that it is still part of the language. Linguists predict its disappearance could take place by 2066. It is commonly replaced with “d,” “v” or “b” depending on the word.
The third and this is especially common for people from Latin America is to place an unnecessary “a” or other similar vowels sounds at the start of a verb. ‘I will be a-going to the store tomorrow’ just doesn’t sound natural or modern, especially from someone born outside of an English speaking country. It is true that some British and American accents could reflect this, but, especially in the United States, it is not considered proper.
What helps you overcome these mistakes? A critical friend and tough skin on your part. I’d encourage you to ask your close native speaking amigos to stop and correct you often. It is also very painful, but record yourself (preferably on video) speaking a text such as:
I am sharing these thoughts with you. Once I have shared my thoughts, I think the matter will be closed. I think of it as therapy. Please don’t be scared that I have shared my thoughts.
See what the result is and make a measured effort to improve!