il est probable que

Example

Il est probable qu'il acceptera notre offre.

Do not write

Il est probable qu'il accepte notre offre.

Why

A TRAP, and the exact counterpart of il est possible que. Probability presents the fact as expected: INDICATIVE. Possibility leaves it open: subjunctive. One word separates the two phrases, and the mood changes. The subjunctive is found in good writing, but it stays a minority form: write the indicative.