def _get_clause_words( sentence_text, clause_id ):
    ''' Collects clause with index *clause_id* from given *sentence_text*.
        Returns a pair (clause, isEmbedded), where:
         *clause* is a list of word tokens in the clause;
         *isEmbedded* is a bool indicating whether the clause is embedded;
    '''
    clause = []
    isEmbedded = False
    indices = sentence_text.clause_indices
    clause_anno = sentence_text.clause_annotations
    for wid, token in enumerate(sentence_text[WORDS]):
        if indices[wid] == clause_id:
            if not clause and clause_anno[wid] == EMBEDDED_CLAUSE_START:
                isEmbedded = True
            clause.append((wid, token))
    return clause, isEmbedded