the form
and style of the letter must be suited to the message which the letter
contains, and to the relationship which exists between the person who
sends the letter and the one who is to receive it. The style of
business letters must be clear, direct, and dignified. With certain
exceptions, as in sales letters, such letters are usually made very
impersonal. On the other hand, personal letters are quite properly
regarded by many as a sort of conversation in writing. In writing to
friends or to relatives one usually desires to be informal. One of the
ways of achieving this informality is through the use of colloquial
English and contractions. In the past, many teachers of English have
cautioned students against the use of contractions in letters; but an
examination of the correspondence of writers whose letters are
regarded as models shows that most of these authors use contractions
very freely. If you will read the letters of Henry Adams, Stevenson,
Gray, Henry James, Lamb, Carroll, Walpole, Keats, Emily Dickinson,
Thackeray, Dickens, and others, you will see that in writing to
friends and members of their families they wrote much as they would
have chatted with those to whom the letters were addressed.

In general, then, contractions are to be used only in informal or
friendly correspondence. In letters to strangers and in most business
correspondence they should be avoided. Perhaps the best guide to the
proper use of contractions is to be found in the models of writers who
are famous for their personal letters.

can't "You can't be too careful." (Lamb)

don't "... for, O, I don't know how long." (Stevenson)

doesn't "He doesn't agree with them all ..." (Stevenson)

won't "This sort of thing won't do." (H. James)

it's "... It's a glorious afternoon ..." (E. Dickinson)

I'm "I'm three parts through Burns; ..." (Stevenson)

I'll "I'll try to improve it ..." (Stevenson)

haven't "... I haven't yet had time to give ..." (H. James)

you'll "You'll never guess; ..." (Carroll)

isn't "It isn't like gold ..." (E. Dickinson)

I've "So I've been idle." (Stevenson)

we'll "We'll finish an education sometime ..." (E. Dickinson)

wouldn't "... but Stephen wouldn't allow it ..." (Stevenson)

didn't "... I didn't see him." (Fitzgerald)

I'd "Another shot and I'd have gone to kingdom come." (Stevenson)

you'd "... and I beg you'd beli