Usage: “In order to” can be used to introduce an explanation for the purpose of an argument.
Example: “In order to understand X, we need first to understand Y.”
2. In other words
Usage: Use “in other words” when you want to express something in a different way (more simply), to make it easier to understand, or to emphasise or expand on a point.
Example: “Frogs are amphibians. In other words, they live on the land and in the water.”
3. To put it another way
Usage: This phrase is another way of saying “in other words”, and can be used in particularly complex points, when you feel that an alternative way of wording a problem may help the reader achieve a better understanding of its significance.
Example: “Plants rely on photosynthesis. To put it another way, they will die without the sun.”
4. That is to say
Usage: “That is” and “that is to say” can be used to add further detail to your explanation, or to be more precise.
Example: “Whales are mammals. That is to say, they must breathe air.”
5. To that end
Usage: Use “to that end” or “to this end” in a similar way to “in order to” or “so”.
Example: “Zoologists have long sought to understand how animals communicate with each other. To that end, a new study has been launched that looks at elephant sounds and their possible meanings.”