Say what? You can tell your BFF almost anything, so why can't you tell her what's been on your mind? Is it because she's peeved you or is plucking your very last nerve? Or maybe it's just something that would make for downright uncomfortable convo. Stash that thesaurus, and let GL help you find the right words for what to say ....

Often, there are things you wish you could say but can't--or think you can't. Telling a friend something that might hurt her, scare her or make it seem like your concern is really just sniffing around her biz can be big-time tough. According to psych experts, it's the anxiety of anticipating a worst-case scenario that keeps buds from bringing up iffy subject matter. The worries pile up: Will she dump me as a friend? Never speak to me again? Spread rumors? In reality, none of that is likely to happen. She's your best friend. So why are you still so tongue-tied? We asked GL readers for their most common BFF conversation quandaries, and we're right here to tell you what to say to your best friend when ...

... SHE FLIRTS WITH YOUR CRUSH

WHAT TO SAY Girls flirt. Some flirt better than others and, when one flirts better with your crush, you might daydream about shaving her head with a butter knife. "My best friend pays more attention to the guy I like than to me," e-mails Bianca, a Las Vegas sophomore. "When she finds someone to like, I'm going to send him roses or something. I'm so pissed!"

Maybe your friend likes him, but since she's your BFF and openly flirting in front of you, our bet is she feels brave because she's actually not after him. Tell her you really appreciate that she's being cool to your crush and helping you attract him, but that pulling back just a little would be a lot more helpful.

AVOID THIS Accusing her of wanting him most likely will cause a rift. If you truly suspect something is up, ask her straight-up if she likes him. Crazier things have happened.

... SHE ASKS TO BORROW YOUR CLOTHES--AGAIN

WHAT TO SAY Have a friend who thinks your closet is shopping central? "This one is easy," writes a Los Angeles reader. "Tell her you get in trouble if you lend your clothes out." We're not advocates of white lies ... unless they get you in the door at a concert or get your BFF off your back about nabbing your brand new Citizens For Humanity jeans.

If she knows you won't get grounded, let her borrow that blouse but only under these conditions: 1) She replaces it if she ruins it. 2) She gives it back the next day. 3) She gives it back clean. Shake on it.

AVOID THIS Skip the trip down memory lane of everything she's ever borrowed plus a tally of what she'd owe if she actually paid for the stuff she destroyed. This isn't Teen Court.

... SHE GETS YOU IN TROUBLE

WHAT TO SAY She cheats off your final exam and gets you busted? She Sharpies, "[Your name here] loves Sk8Rboi 4VR," on a cafeteria table, and it's your butt in the office? Two questions: 1) Has she been in trouble because of you? If so, you're even. 2) Was the punishment a big deal? If it was boring and lame, tell her to cut it out and let her buy you a blended coffee.

She's your BFF, which means she gets your forgiveness. If it keeps happening, tell her you'll tell she-knows-who that she wants to you-know-what with him. Secrets are good ammo.

AVOID THIS Crying, screaming, throwing yourself down and hollering, "Lady justice hath no mercy!" is awfully dramatic. For suffering what? A whole hour of detention? Oh, please.

... SHE TRIES ALCOHOL OR CIGARETTES

WHAT TO SAY If alcohol slogans were honest, they'd look like this: "Alcohol tastes bitter but, if you add a sugary juice, it will make you all goofy until you get to vomit for a few hours before it possibly gets you killed in a car accident!" At least cigarette ads are already in your face about the harm they do. So, what to do if your BFF is dabbling?

"'Don't be such a baby,' was exactly what Karrie said to me, as if drinking was nothing big," writes a reader about her BFF in Texas. Tell her you get why she's curious but that it's not cool so knock it off or you'll tell her mother! We don't care if that's charged advice. Booze and butts? No and no.

AVOID THIS Thinking of joining in the reindeer drinking games? Don't make us come over there.

... SHE HAS A ONE-TRACK MIND ABOUT HER WEIGHT/A GUY/WHATEVER

WHAT TO SAY "Please make my friend stop talking about what she eats every day," writes Claire, 17. This came from Shelly, 16: "If I have to listen to one more story about my BFF's BF and every detail of what he says, I'll punch her."

People don't realize when they're obsessing and boring everyone to tears. First, try changing course with this: "Oh! That reminds me ..." Even though the subject may not detour entirely, you switch gears on your BFF's focus. If that doesn't work, tell her you're interested in that stuff but you want to know if she thinks Nicole and DJ AM will get engaged again.

AVOID THIS She probably has no idea her mind is stuck on replay so shouting, "Shuddup already!" when you've reached the end of your patience rope will only shock and hurt her.

.. SHE GETS A BOYFRIEND

WHAT TO SAY if you have a BF, this is outstanding news--double dates! If you don't, welcome to your new abundance of quality solo time. "My BFF didn't ditch me, but she was with her new dude after school every day and wouldn't make plans for the weekends because she was always waiting to see what he wanted to do first," writes Allison, 14, from Oakland, Calif.

It can't hurt to gently remind your friend that her new guy will be more into her if she stays the person she was when he decided he liked her, which means she did her own thing. Leave off the detail about how "her own thing" included you.

AVOID THIS Sulking or acting all hissy will only convince her you're jealous. If you want to hurt your friend and drive her away, try talking trash about her new BF. Works every time.

... SITE MAKES A NOT-SO-FUNNY JOKE AT EXPENSE

WHAT TO SAy There's a big diff between an intentional diss and a careless blurt. "My BFF was kidding around at lunch, and I jumped up to join in, and she said--really loudly--that she could see my pad," writes Khristina from a town on the Oregon state line. "My crush and his friends were right there."

This isn't always easy, but the best in-the-moment reaction is to blow it off. If you can laugh it up with the crew, everyone will totally forget about the ordeal by next, uh, period. Getting mad or making a scene draws more attention to an already embarrassing situation. Later, in private, you can tell her you know she didn't mean it but that it was sorta humiliating. Then, tell her to stop looking at your butt.

AVOID THIS A counter attack of, say, announcing her chronic flatulence problem, is intentional and mean. It's also gross, and no one wants to hear it.

... SHE ACTS LIKE YOUR SOCIAL SUPERIOR

WHAT TO SAY Competition can create more hysteria than Paris and Nicole showing up at an event in the same dress. "I couldn't keep up with my ex-BFF," says a reader from Seattle. "She had to be the best student, have the hottest guy, drive the most expensive car--and she rubbed it in my face. It was like being friends with Barbie."

Looking at someone's life and believing she has it made is naive. Everyone has problems. If you suspect your friend feels first-rate to your second, here's the truth: She actually feels inferior. She's laying it on thick because she's trying to convince herself that she's great. So help amp up her confidence. Tell her all the ways you think she's awesome and how nothing will change that. Unless you get a reality TV show together.

AVOID THIS Getting up in her grill with your own gloating is counter-productive. Friendship is a shared experience, not a contest. So no need to compete.

... SHE BREAKS UP WITH HER BOYFRIEND

WHAT TO SAY A freshly broken heart is a pummeled heart, often leaving a girl with the energy and enthusiasm of a used Swifter sheet. "All my BFF did when her boyfriend dumped her was lay in bed listening to that song 'Don't Speak' by No Doubt," writes Michelle, 16. "I tried bringing her food, I rented funny DVDs, and I kept saying she's better off without that fool."

Truth is she could be better off, but that doesn't matter to her just yet. With a fresh breakup, it's raw emotion flailing in a lonely wind. The best thing you can say to her? Keep promising her that she will get over him soon and that you'll be right there for her while she heals.

AVOID THIS Dissing the guy or sharing gossip about him almost always backfires. You might also consider swapping that No Doubt CD for JoJo's "Get Out, Leave."Just a suggestion.

... SHE TELLS YOU HER PARENTS ARE GETTING A DIVORCE

WHAT TO SAY No matter how you slice up the divorce pie, your friend is going to be hurting, confused and maybe even angry. "My parents each rented condos in different parts of the city after they separated," says Lynn, 16. "My two best friends constantly made a huge deal out of coming to pick me up, even though it was only like another 10 minutes into town." Harsh, right?

When someone is managing difficult feelings, they need more of everything from friends. More patience, more help, more understanding, more attention. Make sure she knows that you get how hard it is when parents split and that she can count on you anytime. Even if you have to go out of your way.

AVOID THIS: Dishing out flack about stuff like being inconvenienced when your friend's parents divorce is right up there with stonewashed denim. It's just wrong, and no one will like you for it.

... SHE TELLS YOU A LOVED ONE HAS DIED

WHAT TO SAY "My cat was 13 when she died," remembers Jana, 16. "I called her 'Sister Kitty' because I'm an only child and got her when I was barely 3. I called my best friend about 100 times to tell her Kitty had passed. She finally called back and said, 'Jana, it was only a cat.'"

Dear Jana's BFF, Insensitivity called and says it wants its heart-stomping boots back.... Everyone mourns differently, but all agree on the same etiquette when comforting a grieving friend: Just be there. Let her cry, or let her be silent. Listen and listen and listen some more. When it's time to reply, tell her you're not going anywhere and that you'll help her get through this. Tip: Offering to loan her that unloanable item she's asked to borrow 67 times would be a bonus.

AVOID THIS Saying, "I'm sorry," is a common response but puts responsibility on the grieving friend to comfort you. Oh, and complimenting her good sense to use waterproof mascara is entirely unnecessary.

So there you have it. Telling it like it is won't extinguish the friendship. It's how you tell her that could influence the outcome. If you're gentle and mature when it comes to speaking your mind, she'll know you mean well. And the odds are overwhelmingly good that you'll come out even better friends for it. Can't beat that.