So coming first or last does make a difference then!
Which, in your opinion, is more typical of spoken English: example (1), where then is in initial position in the clause call him or example (2), where then is in final position?
1) Sharmila: If you like him, then call him
2)Ann: I like him
Joe: call him then
Alexander Haselow points out that in final position connectors such as then are very frequent in spoken language, whereas in written language they are almost non-existent. This indicates, he explains, one of the essential differences between spoken and written language – the fact that spoken language is spontaneous and unplanned. In the initial position of a clause, as in (1), then explicitly links call him to if you like him and guides the listener to interpret call him as a consequence of if you like him. In (2), though, where Joe adds then to the clause after he has uttered it, each clause is presented as a separate idea. It is only after he has expressed these ideas that Joe shows how they are related.
Haselow analysed 1000 tokens of clause-final then in the spoken component of the ICE-GB corpus. He found that speakers use then in final position not only to relate two separate clauses, but also to strengthen the force of what they had just said and even to indicate a range of attitudes towards what they had just uttered. For example, in (3), then strengthens the force of B’s question. In (4), the use of then implies that speaker B is impatient.
3) A: oh he’s fairly happy
B: why do you think he doesn’t write then
4) B: and you were going apparently he would uhm say choo choo choo choo or something
A: I haven’t the faintest idea what you’re talking about
B: well you have to listen to the tape then
When then relates two separate clauses to each other in these ways it helps to organise the discourse. Sometimes, though, speakers in the corpus used then in clause-final position not to link two separate clauses but instead to link an utterance to an idea that was implied rather than actually uttered. Approximately 20 per cent of final then tokens were of this kind in the ICE–GB corpus and all occurred in information–seeking questions beginning with a wh-word, such as what or why. For example, asking a friend what have you been up to today then may not relate to anything that has been previously uttered but may instead simply introduce a topic of conversation, implying that the speaker expects their friend to have been doing something and that the friend will be willing to talk about it.
Haselow concludes that then has developed from a time adverb (and then he kissed me) to a discourse marker (as in examples (2), (3) and (4)) and then to a modal particle (as in what have you been up to today then?), with all three functions coexisting in spoken English today.
Haselow, Alexander (2011) Discourse marker and modal particle: The functions of utterance-final then in spoken English. Journal of Pragmatics 43:3603-3623