He says that he shall teach for two more years; then he shall probably return to college.
119. Use a semicolon to separate the clauses of a compound sentence that are joined by a conjunction, only when it is desirable to indicate a very definite pause.
I have told you of the theft; but I have yet to tell you of the reason for it.
120. Use a semicolon to separate the parts of a compound or a complex sentence, when some of those parts are punctuated by commas.
As men, we admire the man that succeeds; but, as honest men, we cannot admire the man that succeeds by dishonesty.
Wrong: He spends his money for theatres, and dinners, and wine, and for his family he has not a cent.
Right: He spends his money for theatres, and dinners, and wine; and for his family he has not a cent.
121. Use a semicolon before certain adverbs and adverbial expressions, when they occur in the body of the sentence and are used conjunctively; such as, accordingly, besides, hence, thus, therefore, etc.
I do not care to see the game; besides, it is too cold.
John is sick; however, I think he will be here.