My new boyfriend borrowed up to $5500 from a friend, incurring this sum here in there over various months, mainly for gambling, back in 2004/2005. All in cash, nothing is signed however there may be a "friend" who witnessed the odd loan at the poker table. My boyfriend plans to pay it back, we have half saved now but won't have more until the new year once he gets back on his feet and starts working again. We've received a paper from the loaners lawyer friend stating to pay the money back in 30 days or interest will start acruing. My boyfriend has never signed anything, no cheques were ever written, it is ALL verbal apart from the loaner mentioning it in the odd e-mail. Even the amount is in question as nothing was ever documented as far as we know, unless the loaner wrote something down on his own. I don't believe my boyfriend has ever responded to owing him money in an e-mail. Never has he put in writing that yes he owes this money and this is when it will be paid back.
Is he able to take us to court because of this letter sent in the mail? Is he legally able to force us to pay interest after 30 days? I am all new to this so please forgive my ignorance and thank you! By the way we live in Canada - B.C. But the loans were made throughout the Caribbean islands while working on a cruise ship 5/6 years ago.

... Is he able to take us to court because of this letter sent in the mail? ...

He can take your boyfriend to court and, unless a statute of limitations applies, if he can prove the loan he can get a judgment. The letter has nothing to do with it unless the sending of such a letter is a prerequisite to litigation in your jurisdiction. Note that in many places the SOL will be different if it is an oral loan.

He cannot take "us" to court: you don't owe it. Your boyfriend does.