Semantic markers. They indicate how ideas are being developed.

firstly, secondly, finally

Markers for illustrations and examples

for instance, for example

Markers that introduce an idea that runs against what has been said earlier

but, nevertheless, yet, although, by contrast, however

Markers showing a cause and effect relationship between one idea and another

so, therefore, because, since, thus, consequently, for this reason

Markers that show the writer's intention to sum up the message

to summarize, in other words, it amounts to

Markers indicating the relative importance of different items

it is worth noting, it is important to note that, the next crucial point is

Markers used to rephrase what has already been said

in other words, put differently, that is to say

Markers that express a time relationship

then, next, after, while, when