Although "this" or "these" may be used informally, consider one of the suggestions for a more formal or traditional tone.
Although "the reason is because" may be used informally, substitute "the reason is that" for a more formal or traditional ...
Although "the way how to" plus a verb, as in "the way how to go," may be used informally, consider using "the way to" plus ...
Although "the way how" may be used informally, consider using "the way that" or "the way in which" for a more formal or traditional ...
Although "this here" or "that there" may be used informally, delete "here" or "there" for a more traditional or formal tone. ...
Although "this" or "these" may be used informally, consider one of the suggestions for a more formal or traditional tone. ...
Although "to be able to" may be used informally to mean "can," consider replacing the phrase with the more concise "can." ...
Although "under" may be used informally when you mean "less than" or "fewer than," consider using "less than" or "fewer than" ...
Although "way," "way too," "real," "mighty," "plenty," and "awfully" may be used informally, consider rewording your sentence ...
Although a preposition at the end of a sentence may be used informally, consider deleting or repositioning the preposition ...