"Have you been to foreign countries?"
The thing. Literally, Does this thing (that you went to a foreign country) exist? Meaning Have you ever been to any foreign country?
"Have you been to a foreign country" is more accurate since the current sentence in english means "have you been to (multiple) foreign countries"
Since it's not specified in the Japanese sentence, it could be either singular or plural.
If I have been to 1 foreign country only, I should answer "No, I haven't."?
It is like "have you ever had the experience of been in a foreign country" or just "have you ever been in a foreign country", but this form usually isn't used for daylife or commonplace situations.
No, へ would emphasize the direction, which doesn't really make much sense when used with something like 'foreign countries'
Correct me if I'm wrong, but to me, 外国へ行ったことがありますか sounds more like: Have you ever been on your way to foreign countries.
The following quote is from http://www.guidetojapanese.org/learn/grammar/verbparticles (July, 28. 2017) " The primary difference between the 「に」 and 「へ」 particle is that 「に」 goes to a target as the final, intended destination (both physical or abstract). The 「へ」 particle, on the other hand, is used to express the fact that one is setting out towards the direction of the target. As a result, it is only used with directional motion verbs. It also does not guarantee whether the target is the final intended destination, only that one is heading towards that direction."
That's why I would prefer to use に rather than へ in this sentence.
“Have you ever been on your way to foreign countries.” seems a bit of a strange question to me. But I would leave it to a native for opinion.
Tae Kim ! Although I agree with most of his explanation about へ, some points worth a closer look. Firstly it is a bit arbitrary to say へ is ONLY used with directional motion verbs. It is pretty easy to find exceptions, e.g.
I work hard to become a doctor.
Secondly へ does talk about only the direction, but in my opinion it has very limited implication, if any, that the destination is elsewhere. Compare with To and Towards, the distance between に and へ is smaller. If someone says "I go towards Tokyo", I would feel that his destination is probably not Tokyo but somewhere in between, or otherwise he would have said "I go to Tokyo". 東京に行きます and 東京へ行きます would seem to me just 2 different fashions of saying the same thing.
I have heard that "(h)e" is used as "to go" but "ni" implies that you go there with some intention. I'm sure "ni" is far more common. Maybe because there's always something you're going to be doing on the other end!