OK, using these tools doesn’t guarantee success in Japanese learning… look at me for example.
Anyway, one of the things that I love about Macintosh computers is the dictionary feature. You can look up definitions of words easily, via the application Dictionary (duh) or Spotlight search. But what if you are lazy like me and end up neglecting the application? Shortcuts!
What if you can mouse hover on words and with a simple shortcut , a pop up instantly shows up with definitions, pronunciations ? This is perfect! No more launching Dictionary and typing the word yourself.
Well, Google is always so nice and often translates the entire webpage to Japanese for you. But this way you won’t learn because all you see is basically grammatically incorrect English.
1. Look up definitions
No more BS and let’s see how to set it up… ( I learnt about this from my colleague today)

In the Terminal, paste in the command provided below.
defaults write com.apple.symbolichotkeys AppleSymbolicHotKeys -dict-add 70 “<dict><key>enabled</key><true/><key>value</key><dict><key>parameters</key><array><integer>100</integer><integer>2</integer><integer>1310720</integer></array><key>type</key><string>standard</string></dict></dict>”

In System Preferences, go to "Keyboard" > "Services". Check the item "Look up in Dictionary" and click on the right end to customize your own shortcut. Mine is "Cmd-Ctrl-D".

You may need to restart your computer before this step (I didn't). Next, launch Dictionary... Go to "Preferences" and make sure "Japanese-English" dictionary is at the very top. If not, simply drag it up.

Now you're done. Just go to anywhere (websites, email, doc, etc) with Japanese words... You can hover on the target text (no need to select), hold down your preset shortcut. and the pop up will show up instantaneously!
2. Listen to it!
I’m sure many have known and used this Speech feature. I like this feature and use it quite frequently.

Open "System Preferences"> go to "Speech" > In the "System Voice" dropdown, make sure "Kyoko" (the female voice for Japanese) is selected. Also check the item "Speak selected text... key is pressed" below. You are free to modify your shortcut key.

If you don't have Kyoko installed, you can select "customize" from the dropdown menu and install the voice package. It around 300MB, I think... After everything is set up, you simply select Japanese text and hold down your shortcut. Kyoko would read it out with her gentle voice!
Another useful application is to let Kyoko (or any other voice) teach you how to read lyrics of a foreign song. For example, I have used “Yuna” to read out some Korean pop songs. If it happens to be a rap song, just adjust the “Speaking Rate” to “fast”. 😛
Oh, and try to use “Kyoto” to read English text… see what happens. I thought it’d just be English with Japanese accent, but…
–Again, the above tools can be applied to any languages that the Mac supports, as long as you’ve install the corresponding dictionary/voice pack. Happy learning!