If the word used here would have been "b'Atid" -- "In the future," then it would have read, "b'Atid ha'Kadosh Baruch Hu Yachziro (or 'Yachziran')" -- "In the future, ha'Kadosh Baruch Hu will return him (or them."

However, the word used is "l'Atid," without a Beis.

This can be translated as "destined," so the phrase in the Gemara is, "And ha'Kadosh Baruch Hu is destined to return them." In such a form, one uses the infinitive in English as well.

(You may be asking, though, why use this style altogether, and not say simply that Hash-m "will return them"? Perhaps we may suggest that the usage of the wording "Asid... l'Hachziro" is to imply that this event is an important part of Hash-m's intention and Ratzon right now. Had the Gemara used the conventional future tense, it would have merely been saying what will happen in the future, but not emphasizing the "destiny" element of it. -Y.S.)

Kol Tuv,

Dovid Bloom