Or outside of American English you can write "garden".
Yard itself can be translated into German in different ways:
backyard: der Hof and der Hinterhof
shipyard: die Werft
So don't expect every usage of -yard to be -hof. More examples: http://context.reverso.net/translation/english-german/yard
if you click on the lightbulb in the lesson window at the lesson tree you'll find some, not a lot of very general tips. They don't always, in fact rarely, have anything to do with the actual lessons, unfortunately.
In each lesson, there are dotted lines under every word. If you put your cursor over them, you'll see a list of possible translations for each word. Be careful with these though - they are computer driven, not manually supervised (or so I'm told) so they're often misleading and almost never updated.
Quick answer: you're often left to fend for yourself in finding your own tips and tricks here.
I beg to differ, actually. The lightbulb in the lesson window does indeed give tips that relate to the following lessons in that group, but they are only a fraction of the information needed for those lessons. The rest of the information needed for the following lessons (for example, the same conjugations explained, but applied to new or different words) you must figure out for yourself.
There should have been an explanation in the adjective lesson, on Strong Weak and Mixed inflections. (Is there going to be one further down on the tree)? Someone who has no prior experience with German, has no idea what you are talking about. And, the Wiki pages do not help, with all the extra stuff in them. No one cares how this came into being from the Old German.
"wie sind in kleinem Garten" is not a translation of the given sentence. It would tranbslate to "we are in small garden", which is correct only in telegram style, both German and English.
The given sentence contains a definite article ("im" = "in dem"). So the correct translation is "We are in the small garden".