The transitional words that show cause and effect are: so, thus, therefore and consequently. This words will be followed by the consequence or result of an event mentioned before.
English transition words are relevant, because they not only connect ideas, but also can introduce a certain shift, contrast or opposition, emphasis or agreement, purpose, result or conclusion, etc. in the line of argument.
The transitional words used to show case effect include: therefore, hence, thus, as a result, resulting in, so, consequently