Active subreddit where natives answer translation and grammar questions fast.
Details
The most reliable free place to get a handwriting sample deciphered, a tattoo checked before it is permanent, or an explanation of why a sentence uses that preposition, usually answered by native speakers within hours. Also the best place to hear about new Hebrew resources, since the ecosystem is small and word of mouth matters. Traffic mixes Modern, Biblical and liturgical Hebrew questions, so specify which you mean, and quality of answers varies as it does anywhere on Reddit.