Structuring a text

The list an argument is assembled with. Near the top is certes, and it does the opposite of what an English reader will assume. It is not an intensifier: it is a *concession*. Certes, le coût est élevé, mais… means « admittedly the cost is high, but… » — the speaker hands the point over precisely so that mais can take it back, and a certes without a following objection sounds unfinished. English « certainly » insists: « the cost is certainly high » agrees and stops. So reading certes as « certainly » loses the concession and turns the sentence into the argument it was written to answer. The English equivalents are « admittedly », « granted », « it is true that » — and « to be sure », which is the closest and is itself a concession despite looking like an assertion.