The challenge is [to-inf]/gerund

Question

I think I have seen two versions of this structure:

The challenge is [to V]

The challenge is to transform people’s mentality about preventive healthcare, says CEO of Cure.fit.

I take my dreams very seriously and love to rediscover and challenge myself and this time the challenge is to publish my book before February 2019.

The challenge is [gerund]

The blessing part gets me out of my comfort zone, but the challenge is not letting it drain my energy supply.

The challenge here is surviving your friends.

What is the difference between the two structures in terms of meaning? If there are any differences, then when to use to V and when to use gerund?

Would the meaning of these sentences change if we used the other structure? (Like, the challenge here is "to survive your friends" instead of "surviving your friends.")

Answer 1

Usually, the gerund and the to-infinitive are interchangeable. This is the case with all of your examples. However, there are times when they are not interchangeable, e.g.:

This room needs brightening up.

This sentence makes sense and implies that someone will need to brighten the room up.

This room needs to brighten up.

This sentence makes no sense because it implies that the room will need to brighten itself up.

In these two sentences it is obvious that the gerund and the to-infinitive are not interchangeable.

So, usually interchanging these structures is acceptable, but you should always check to ensure that the sense of the sentence is not compromised by doing so.