How difficult is it for Japanese to distinguish between 五日【いつか】 and 何時か【いつか】 in spoken contexts?


There are times when both 五日 (5th day of the month) and 何時か (someday) could be
used I think. Does this become a minor problem for Japanese when speaking (no
kanji to guide), or do they speak in some way to avoid the possible confusion?

A sentence I thought of where either いつか could be possible:

> いつか、アメリカに行きます。

Are they going to America on the 5th of the month, or are they expressing
intent to go to America eventually in the future?




  * For your particular sentence, using `五日` adverbially without `に` under the meaning 'fifth day of the month' is ungrammatical, so it is unambiguously `何時か`. They are expressing intent to go to America eventually in the future. As Tsuyoshi Ito correctly points out below, there is still slight chance that it may be `五日` meaning 'for five days,' but this possibility is less likely because (i) `[五]{いつ}[日]{か}[間]{かん}` is more natural, and (ii) it would usually be written in kanji.

  * Generally, in written form, `何時か` is usually written in hiragana, whereas `五日` is usually written in kanji, so you can usually tell.

  * Generally, in spoken form (in the standard dialect), `五日` has the pitch pattern `いつか{LHH}` (low-high-high), whereas `何時か` has the pitch pattern いつか{HLL} (high-low-low), so they are unambiguous.




  * For your particular sentence, using `五日` adverbially without `に` under the meaning 'fifth day of the month' is ungrammatical, so it is unambiguously `何時か`. They are expressing intent to go to America eventually in the future. As Tsuyoshi Ito correctly points out below, there is still slight chance that it may be `五日` meaning 'for five days,' but this possibility is less likely because (i) `[五]{いつ}[日]{か}[間]{かん}` is more natural, and (ii) it would usually be written in kanji.

  * Generally, in written form, `何時か` is usually written in hiragana, whereas `五日` is usually written in kanji, so you can usually tell.

  * Generally, in spoken form (in the standard dialect), `五日` has the pitch pattern `いつか{LHH}` (low-high-high), whereas `何時か` has the pitch pattern いつか{HLL} (high-low-low), so they are unambiguous.

