The sentence "I shall explain" is correct and can be used in written English.
You can use this sentence when you are trying to make a commitment to explain something to someone. For example: "I shall explain the project's timeline more thoroughly during our meeting tomorrow."
Sorry, I meant, if you haven't seen Anchorman, I shall explain.
For those sweet souls out there whose minds have remained unsullied by the flotsam and jetsam of the fashion world, I shall explain.
Père de Vaux has suggested that there is documentary evidence which may throw some light on this problem, and this I shall explain in a moment, when we arrive at the document in question.
It seems clear to me that in future everybody in the world will want democracy for the political side of life, and the free choice of the marketplace as the basis of economic life.Mahmoud: My picture of democracy may be a little different from yours, as I shall explain in a moment.
No one wants an English parliament, and the Tories are barking up the wrong tree when they propose differential voting for Scottish MPs - as I shall explain, again, when we're all feeling a little stronger, by examining the passage of the Irish home rule bill of 1893.
If you found yourself asking at some point, "Holy Jehosophat, why on earth is Kirk Douglas presenting the best supporting actress award?", I shall explain: it's because last year's supporting actors winners, Mo'Nique and Christoph Waltz, were, respectively, being difficult and away working.
That choice is (as we shall explain) not quite so stark, but Mr Brown has definitely chosen the first course.
"The police shall upon receipt of the information undertake the necessary enquiries and the record shall contain the statements of the witnesses and the employer or his representative and the statements of the injured if his condition so permits and the record shall explain the relationship of the incident to the work.
Now, we shall explain how Mo nanowalls are formed.
To begin with, we shall explain the different decision-making processes, which characterize the teaching act.
Section 3.3.2 shall explain how the battery output power can be adjusted.
