This may seem like an insignificant question but I was wondering why the Hebrew "וְשָׁ֖מָּה" which is feminine appears in Jeremiah 18:2 to refer to "בֵּ֣ית" which is masculine:
קוּם וְיָרַדְתָּ בֵּית הַיּוֹצֵר; וְשָׁמָּה, אַשְׁמִיעֲךָ אֶת-דְּבָרָי
To make tblue's comment into an answer:
This suffix can be loosely translated as either direction (towards X) or distance (over at X). For example, the word יְרוּשָׁלַם yerushala(i)m is suffixed to become יְרוּשָׁלַיְמָה yerushalaimah when Sennacherib sends his servants "to Jerusalem" in 2 Chronicles 32:9. Other examples are "northward" and "homeward".
In this instance, the sense of direction stems from the command to travel to the potter's house. (You might expect בֵּית beit "house" to have the same suffix, but it can't because it's bound to the word "potter".) I would probably capture that sense in translation as "over there" or, more dynamically, "once you're there".
Note that the Bible does have grammatical inconsistencies elsewhere, so it's a valid question.