Conclusion paragraphs refer to the end of your essay. They, obviously, come last in your writing. 

You start by using a word or phrase that indicates the conclusion of your essay. Then, you can summarize the main ideas you have already written, but in different words. Never repeat words as they are from the essay or from the question prompt. You can restate your opinion if you were asked to provide your opinion depending on the task two question type. Additionally, you can for instance provide a recommendation or a suggestion. 

Check out the example below. 

In conclusion, it can be deduced that the advancement and survival of humankind should be the principal purpose of science. As a result, it is recommended that governments support those who work hard to make this possible.  

Words and phrases to refer to conclude as follows:

To conclude, / In conclusion, ……

To sum up, / To summarize, / In summary, ……

To recapitulate, ……

To reiterate, ……

Stated briefly, ……

To recap, ……

In short, ……

From the analysis/argument above, we can conclude that ……

From the aforementioned argument, a conclusion can be drawn that ……

To bring this essay to a close, / To bring this essay to an end, ……

In the abstract of this essay, ……

In this essay, I have attempted to shed light on …… (preferred in opinion essays)

On balance, the overall picture seems to be that ….. (preferred in discussion essays)

In the final/last analysis, …..

N.B.:

The words “lastly”, and “at last” can be confusing to many people. Lastly indicates the final point of a list or a series of points being discussed. It is similar to the word “finally”.

The phrase “at last” refers to the occurrence of an event people have been waiting for. It is similar to eventually.