I had an idea that thinking of your own sentences is too easy. How about we give each other sentences in English to translate? I’m gonna write some for you, in increasing difficulty (or at least I think they’re in that order of difficulty, I’m still a noob at Japanese), so that (hopefully) every level of learner can find something:
For every you translate, assign another to others.
“The sky is blue.” > 空は青いです。
That dog (near the listener) is cute.
その犬は可愛い(kawaii has kanji?! Ok, Windows IME)です。
“It’s your duty to love it, or change it."
4.“Fear is the little death that brings total obliteration.”
Sorry, could not resist.
留守する間は何時間くらいと思うですか
“Even if I had wings and could fly, I would be too lazy to use them”
By the way, I just found out by accident that, when you select text from another person’s post, a popover appears for you to “quote” the selected passage
彼は足首のため、好きじゃない
“I want to like him despite his ankles” HA =)
Surprisingly, this is more fun than I thought
Hey 
I would say:
(彼女が)出かけるのは何時間くらいだと思いますか？
Advice: keep it simple. 
Generally, you cannot use です after verb in short form. The exception are a negative form of verb and explanatory tone.
Ops, thanks for the です correction. On the other hand, I could not grasp what was the simplification brought about by changing “留守する間は…” to “出かけるのは…”. Could you elaborate ? Actually, does it sound more “natural” the second way ? (I cannot say…)
In many cases, する verbs are thought to be a bit more formal, the する analogs of ordinary verbs are used for example in writing (something along I do not vs I don’t, or maybe using latin names of animals instead of the ordinary ones ). Examples are: 認識する instead of 知る、理解する instead of 分かる etc. (it is not always the case though!)
By the way, another way to convey the intention of the speaker would be:
彼女、いつごろ(or 何時ごろ)戻りますか（,帰りますか or 帰ってきますか) ？
By the way, sentences were great
“It’s your duty to love it, or change it."
あなたの役目はそれを愛することか変えることだ
That’s probably either really stilted or weird? But Google understands it, that’s encouraging 
(Sidenote: If I were to say this to someone else, I really ought to use their name (+さん ) instead of あなた, or else I’d be rude, right?
Oh and also… not sure if それ is such a good choice for an object here (or if its really needed)?)
So I guess we need more sentences, huh? How about
cmiiw. ^^
No.4 and 5 basically too hard for me haha, it’ll be nice if someone can do some corrections on them~
Two possible improvements:
First, you might be better off using である here, given the kind of style the sentence is from (It’s the opening sentence to A Tale of Two Cities, by Charles Dickens, and is delivered in a very authoritative and poetic style).
Second, a conjunction of some form is probably in order. This could be で, or better yet ば. The best fit I can think of would therefore be でもあれば.
I’m nearly certain that the “official” translation would opt for different word choices, also, but we’re just here for the grammar. 
Hint: if the verb is ある, you probably want to be using に. 
Also, for seasons, you probably want to stick to the generic counter, so something like ここには季節が２つしかない。
Ooh you’re so close! 
First, since it’s the seasons that are coming, you probably want が来る.
Second, it might be better to use something like と instead of 時, depending on if there’s any causality implied (it’s not certain from the English, I don’t think)
Third, you probably want to make the embedded clause into a question: 何がおこるか教えてくれるの？
Here’s my shitty attempt.
あんたったら、なんでいつも「なんで」が出るのか？ なんで僕が「結婚しよう」って言うたびに
なんか「はい」ってさえ言えないのか？！
Too strong? Probably 
I’m also a bit shaky on a lot of this stuff. Probably gonna get a native to tear it to shreds for me. 
EDIT: Totally forgot Revel’s sentences! 
And finally, my contributions to the pool:
・新しい帽子が（大）好きですよ。
・新しい帽子が好きだって言ったって信じられる？
・まあ、帽子の新しさはすごく目立っているよね。??? 
???
まあ、正しいと思えないけど…
それに、本来の文章からちょっと脱線してすいませんでした
・I need new shoes.
・Why don’t we go shopping at the new store?
・Even if I worked every day of the week, I would not be able to afford new shoes.
いやいや、良いかもしれない。☆彡
ところで、文プロへようこそ～
ありがとう〜
ずっと前に登録したけど、あまり使わなかったね。今度基本中の基本を復習するために戻ってきた！よろしくね。
日本に住んでいるの？文法の能力は高そうだね…
まあ、住んだことがあるんだけど、帰国させられてしまった
@Wonkyth どもありがとうございます！
あー！particleですね。。二年ぐらい日本語を勉強したけど、まだむずかしいとおもいます
Logicはまだ見つけらない（笑）
新しい文章お願いします：
・この辺に、安い靴を売っている店を知っていますか？/店がありますか？
・友達は日本に住みたいって言ったけど、漢字を勉強するのを拒んだ。
（拒むって使えますか？）
・うそだろう！無理っすよ！うそつき！
“I will fall asleep every time while reading a novel”
Couldn’t find a natural way of saying this… 読みながら、読んでいる間、読む時 etc, don’t know which one to use and which way of “falling a sleep” makes sense.
When did you come to Japan?
I don’t have a dog. I have a cat.
Do you want the blue or the green shirt?
Don’t come closer!
I can’t imagine that being the case!
Jumping in despite my grammar being way lower than the rest of you guys’!
日本にいつ時来ましたか。
犬は持っていません。猫は持っています。
青Ｔシャツか緑Ｔシャツが欲しい？
Not sure on any of these. Corrections are welcome, very welcome.
I’ll add three more sentences:
Why can I never be correct?
Would you believe that? What in the world?
Come here, kitty. I want to eat you. Nom nom nom.