Properly speaking, it is our heart.

准确地说，是我们的心。

Properly speaking, he did not enter.

严格地说，他并没有进来。

Properly speaking, it is not the case.

严格说来并非如此。

Properly speaking, a whale is not a fish. .

严格地说，鲸鱼不是鱼。

That is not, properly speaking, a dictionary, but a grammar.

严格说来；那不是一本词典，而是一本语法书。