Bereft and bereaved are both past-tense and past-participial inflections of the verb bereave, which means to leave desolate or alone, especially by death. By convention, bereaved is appropriate in reference to someone who has lost a loved one by death, and bereft is better in reference to other types of losses. For example, one might be bereft of one’s house after a hurricane. In this sense, bereft carries connotations that the uninflected bereave has lost; the uninflected form almost always refers to relates to deaths of loved ones.
Examples
In these examples, bereaved refers to someone who has lost a loved one by death:
Despite the prevailing sorrow, visitors might gather around platters of food in a bereaved family’s home and celebrate a long life. [Forbes]
The way we treat our bereaved Armed Forces families speaks volumes about us as a nation. [Telegraph]
The government would also make a financial contribution to the families of the bereaved, to cover funeral expenses. [Herald Sun]
And in these sentences, bereft refers to other types of losses:
And how this city, for reasons that can never be completely explained, has been so bereft of sporting stars of the highest calibre. [Toronto Sun]
Having faded into obscurity at 40, bereft of even a single butler to send to the bread line, Fitzgerald wrote his most well-known essay from a rented room in a cheap hotel. [Wall Street Journal]
Short of money, the regime is also bereft of friends. [Financial Times]