While many Olim have succeeded without spoken Hebrew, this is the exception and not the rule.
Plan on needing at least spoken Hebrew within your first two to three years.
Reading will be a major benefit.
Writing in Hebrew (for those of us that don’t learn this as children) is not nearly as important, and many Olim succeed without ever reaching this level.
All new Olim are entitled (and expected) to take a course in Ulpan. These are special classes designed specifically for new Olim to learn Hebrew, and the best are full-time (5-6 hours a day, during the morning and early afternoon) courses which run 5-6 months.
Don’t think that you can come to Israel knowing little or no Hebrew, and walk out of Ulpan 6 months later being fluent! The basic courses (Aleph and Bet) will teach you the basics (The Aleph-Bet, the structure of words, the tenses and genders) however learning vocabulary is mostly up to you.
In short, it’s a good idea to learn some Hebrew before you come, and expect to continue learning Hebrew past your Ulpan experience.
