I would like to express that I happened to see a piece of news on TV when walking past the living room. Can I say, "I saw a snippet on TV."
And which is more appropriate?
- "I watched a snippet on TV"
- "I saw a snippet on TV"
Generally, the difference between "I watched" and "I saw" would be intention. 'Watching' carries the idea of continuously observing, so you watch something out of choice. If you deliberately sat down to view a television show you would say "I watched it". By contrast, "I saw" carries the idea that something caught your eye or that you chanced upon seeing something - for example, you might say "while at the store I saw my friend". When it comes to television, saying "I saw that show" could imply you were just casually watching live television without any particular intent, and the show happened to come on.
With your specific example of a 'snippet' (or some might say a 'clip', or a 'segment' when part of a news broadcast or magazine programme), it seems more appropriate to say "saw", partly because of its brevity but also because we don't always know what to expect on news broadcasts so everything we see on them is by chance.
However, you should note, however, is that speakers of American English do tend to use 'saw' in connection with movies (ie "I saw that movie"). To a lesser degree, British English speakers use "saw" to refer to the manner in which they watched a movie (eg "I saw that at the cinema").
In your question you say "...when walking past the living room".
If you want to say that your seeing this news was almost by accident as you were doing something else, you can use the verb catch or happen:
As I was on my way to the sales presentation, I caught some breaking news on the TV in the building lobby.
As I was on my way to the sales presentation, I happened to see a breaking story on the TV in the building lobby.
In the United States, we would probably say it like this:
"I saw a news clip on TV."
or: "I saw part of a news clip on TV." if you didn't see the whole thing.
or: "I saw a news story on TV."
"I saw part of a news story on TV."
or: "I saw a news piece on TV."
"I saw part of a news piece on TV."
or: "I saw a news segment on TV."
"I saw part of a news segment on TV."
I'm a born-and-raised American, and snippet sounds a little off to me. The word usage is comprehensible, but it sounds like a word choice a foreigner would use. Maybe in another country snippet sounds natural. I would personally most likely use "news clip." I might also use "news story" or "news piece."
If you want to use "snippet", I think you should probably use "news snippet" rather than just snippet. Snippet could mean anything: part of a movie, part of a reality show, etc.