I'm quoting just a single sense from this word because it's so interesting to me. I've already commented on this word a bit here.
afraid, ppl. a.
2.c. with depend. cl.: lest, with subjunctive, introduces a deprecated contingency of which there is danger; that, with subjunctive, an unpleasant possibility; with indicative, an unpleasant probability or contemplated reality. The conjunctions are sometimes omitted. I am (or I'm) afraid: often used colloq. with little or no implication of fear or danger, in the sense of ‘I regret to say; I regretfully or apologetically admit, report, etc.; I suspect; I am inclined to think’. Const. that, or simple clause.