That sentence is however the correct declension for when there's no article (no dem or einem). The thing is, we would usually need an article for a singular object, hence your sentence doesn't sound right (and is specifically not an accurate translation of the English sentence, which has "the" in it).

There are some specific situations where you wouldn't use an article though - newspaper headlines being one. For example: "Escaped prisoner found in small garden". Headlines can also be written like this in German, in which case you'd use in kleinem Garten.

No. You can ask:

• "Wo sind wir?" - (Wo - dativ).

"Wir sind im kleinen Garten." - in+dem = im

And about "kleinen", weak declension is used when the article itself clearly indicates case, gender, and number... http://www.canoo.net/inflection/klein:A (Dativ: dem kleinen)

Unfortunately not. "Wir sind in kleinem Garten" would be incorrect.

A possible sentence would be: "Wir sind in einem kleinen Garten" ("We are in a small garden"), but this is not the equivalent of the English sentence given in the exercise.

Another translation of the English sentence "We are in the small garden" would be: "Wir sind in dem kleinen Garten". In this case, you would not use the preposition "im" (combination of the preposition "in" and the article, dative case, "dem"), but instead use the preposition and the article as separate items.

This, however, would need some context. For example, if there was a large garden ("großer Garten") very close, you could say, to make very clear which garden you mean: "Wir sind in dem KLEINEN Garten".

But normally, without such a context, you would say: "Wir sind im kleinen Garten".

I thought that too but checked out the tables and all genders of dative with a definite article take an -en ending. For weak inflection, all plurals and masculine accusative also take -en with everything else being -e.

The garden is not in the accusative; it's in the dative case.

in takes the dative case when describing a location.

It's written in the table in the link R.Dysangelium gave here. http://www.canoo.net/inflection/klein:A Under - Schwache Flexion (mit bestimmtem Artikel)

That would be "We are on the small garden."