Help! Stop Microsoft word from automatically changing input language

[Raphilion]

I begin to type something in word under English format (Left to right) when suddenly it changes to Hebrew format (Right to left). It seems to happen especially when I use a hash "-"... For example I'll write one word then followed by a space and hash (word1 - word2) But before I can write the second word it starts writing in right-to-left format so it ends up like this; (word1 2drow-).



Please tell me what settings to change or what I must do to stop this annoyance.
Thanks in advance.