There are four basic temperament languages and multiple dialects. Each person gains exposure to all four as they are growing up. Generally speaking, one of the languages will come much more naturally than the others although many people become fairly fluent in more than one. Few people if any are good in all four.
The language of Guardians is rooted in the past. Their talk includes a lot of past tense. Their language is the most traditional of the four. A lot of what they say depends upon multiple social assumptions. For example, a Guardian might say, "Come visit any time you're in the area!" What the Guardian probably means is that they have enjoyed your company. They certainly wouldn't expect you drop in without warning. If they really mean that they want to see you again, they'll pull out their PDA and put you in.
The language of Artisans lives in the present, that infinitesimal moment which divides the future from the past. Their language is likely to include the latest slang and happenings in what is important to them. Much of their language is present tense. Even when they are retelling something that happened in the past, they are likely to use the present tense to make the story more immediate and real.
The language of Rationals is based on the eternal or what can be proven to be true. Rationals are generally concerned with using the right word to accurately and expeditiously say what they mean. Their language tends to focus on ideas and abstract concepts with little focus on feelings or emotional well-being.
The language of Idealists is based on the future. Idealists look ahead to what they can see the future holds. When they talk, they often talk about what will be rather than what actually is. They can see the trends of people's behavior. Their language focuses on the abstract, like the Rationals, but focuses more on feelings and emotional well-being and less on ideas.
Let's look at how each temperament might say, "That outfit looks good on you." A Guardian may say just that or they might say, "That outfit really brings out your best features." An Artisan is more likely to say, "You look like a million bucks in that!" A Rational may not notice the outfit, but if asked to comment, is likely to say something like, "Nice." A Rational who has learned the art of compliments will give a much more satisfying response. An Idealist might say, "That outfit looks great on you! You look so self-confident!"
Now let's look at how each temperament might say (when asked for an opinion), "That outfit looks bad on you." Depending on the kind of Guardian, they might say, "That outfit doesn't do anything for you," or "The color's great, but I liked the first outfit better." Again, depending on the kind of Artisan, they might say, "Change," or "I've always thought you look great in your navy outfit." A Rational is likely to say, "I don't like it." An Idealist might say, "Let's go see what else you've (they've) got to make this outfit really you."
The point of this is that knowing a person's temperament can help you interpret their words. If an Idealist Champion says, "You are so smart!" it means something different than if a Rational Architect says the same thing. The Champion would be encouraging you while the Architect would be saying that they are impressed with your knowledge or intellect.