"interesting to be watched" versus "interesting to watch"

Question

Up to now I still get confused about this grammar. I don't know and also want to know the terminology for this kind of grammar.

Consider the following sentences:

1. This is a video that is interesting to be watched by every student.
2. This is a video that is interesting to watch for every student.

Are both sentences grammatically correct? If they have different meaning, what is the difference in meaning?

Bonus Question

Let's just consider, for example, the first sentence above. How can I make the subordinate clause an adjective modifying the book? Is it correct to say as follows?

This is an interesting-to-be-watched video.

Answer 1

The construction interesting to VERB implies that the person who is interested is the subject of VERB.

• If I say "This video is interesting to watch", with no further qualification, I mean that when I watch the video I am interested.

• If I say "This video is interesting for students to watch", I mean that when students watch the video they are interested.

Now: It is possible for VERB to be cast in the passive. For instance, if I enjoy being the center of attention I may say

It is interesting to be watched

meaning that when I am watched I am interested. And if I teach an entire class of self-centered students (which is not unlikely), I may say

It is interesting for students to be watched

meaning that when the students are watched they are interested.

But you cannot say This video is interesting to be watched, because that implies that when the video is watched the video is interested, which is nonsense—a video is inanimate, it has no feelings, it cannot be interested.

As to your final question: obviously you cannot speak of an interesting-to-be-watched video, or anything else. You might speak of an interested-to-be-watched student; that would be grammatically meaningful, but not at all idiomatic.

English really really dislikes putting adjectives in the 'attributive' position (before the noun) when they have following complements: it makes it difficult to parse the relationship between the adjective and its head, the noun it modifies. (That's why that sort of construction has to be hyphenated.) There are a few phrases which tolerate this sort of construction (easy-to-read, ready-to-wear, and the like), but I advise you to avoid it until you have a lot more experience with the language.

Answer 2

It can be confusing since watch means to look at continuously, and being watched means for someone else to look at the subject continuously.

Let's add commas to sentences to clearly indicate the division between phrases (they aren't required, just adding them to show phrases):

This is a video, that is interesting, to be watched by every student.

That is interesting and to be watched by every student are phrases that modify video.

This is a video, that is interesting to watch, for every student.

Here, that is interesting to watch modifies video, and for every student modifies that is interesting to watch.

It really should be that could be interesting to watch since the speaker can't read the minds of the students.

---

Per your bonus question, what you did is OK. Interesting-to-watch would also be OK. I think you can get away with this for watched/be watched because a video is something that you obviously watch, not something that can watch you.

Note that constructs like this are used for dramatic or literary effect, and not really an "official" (for lack of a better term) way of making adjectives in English. So do this very sparingly.