The word for "fall": taoreru vs. korobu (倒れる vs. 転ぶ)

倒れる "taoreru" is used for objects that fall down while stationary. Therefore, this is used for inanimate objects and for people who collapse.

転ぶ "korobu", on the other hand, is used for objects that fall while moving, so this is used for events like slipping while skiing or skating.

Reference:
Akira Miura, Essential Japanese Vocabulary, Tuttle

Different kanji for "akeru" あける：開ける、空ける、明ける

Jim Breen's EDICT doesn't really provide the difference between the three different ways to write "akeru": 開ける、空ける、明ける, so I'm going to write this article for my reference. I hope others will find this useful as well. All definitions come from Kenkyusha's 5th Shinwaei Chuujiten and the Daijiten (研究者新和英中辞典・大辞典) as well.

"How long" in Japanese

The question phrase "how long" is usually expressed using by any of the following: どのくらい and どれくらい. This source says that, according to the 日本文法大辞典, どのくらい was commonly used in the Edo era, but どれくらい became more common in the Meiji era. Google Search shows that both are still commonly used today. くらい is loosely translated as "about" or "approximately".

どのくらい/どれくらい待ちますか。
Dono  kurai/dore kurai machimasu ka?
How long will we wait?

 あなたは日本にどれくらい住んでいますか？
Anata wa Nihon ni dorekurai sunde imasu ka?
How long have you been living in Japan?

You can also be more specific by using 何日、何時間、何ヶ月, and so on.

毎日、何時間、仕事をしますか。
Mainichi, nanjikan, shigoto wo shimasu ka?
How many hours do you work every day?

何日ぐらい滞在しますか。
Nannichi gurai taizai shimasu ka?
About how many days will you stay?


Source:
jisho.org
Google search
Japanese for everyone

「そのとなり」

More commonly, we encounter position words such as となり, そば, まわり etc in the following grammatical construct:

____ の<となり、まわり, etc>

Interestingly, one of the things that is not taught is the construction

この・その・あの<となり、まわり, etc>

I've seen only そのとなり used (Japanese for Everyone by Nagara), and it means "the one beside it". However, I see no reason why it cannot be used for この・あの. Apparently, it's not very commonly used with そば, although it is commonly used with まわり based on Google Search.

volitional + to omou ～おうと思う

"volitional + to omou" = "to intend to do such and such", "to think of doing such and such"

When talking about a third person, use "to omotte imasu."

ex. 今晩は薬を飲んで早く寝ようと思います。
Konban wa kusuri wo nonde hayaku neyou to omoimasu.
I think I will take some medicine and go to bed early tonight.

姉はアルバイトを探そうと思っています。
Ane wa arubaito wo sagasou to omotte imasu.
My older sister is thinking of looking for a part-time job.


Reference:
Schaum's Outline: Japanese Grammar

The word for "have": 持っている vs. には～がある/いる

Disclaimer: I didn't get this from any book, but this is something that I picked up by hearing these two expressions many times.

Consider the following sentences in English:

1. I have a car.
2. I have two brothers.
3. I have talent.

In English, the idea of possession of a "car", "brother", or "talent" are all handled by the same word, "have". However, in Japanese, there's another nuance that has to be taken care of.

What's the difference between having a car and a brother? One difference here is that you will always have a brother - it's something that's part of you - while you can buy or discard a car. Having a "brother" is inherent, and having a "car" is not. Note that this divide also holds for possession of animate/inanimate objects. Having a "cat" is inherent, but having a "house" is not.

In Japanese, these two nuances are covered by two different sentence patterns: ～を持っている (lit. to hold), and ～に～がいる/ある (lit. to exist in).

"while" - ながら

Note that when using ながら, the subject must be the same for the two actions that occur together! If not, use あいだ.