IndentationError expected an indented block in phyton

Question

Hi I i keep getting that error and I looked everything is right. I google the error it says i am missing a colon after each function but i do have that.

def pH2Category(pH):
    if " pH out of range":

    elif pH<0: and pH<=2:
        category = "Strongly acidic"
    elif pH<=3 and pH<=5:
        category = "Weakly acidic"
    elif pH<=6 and pH<=8:
        category = "Neutral"
    elif pH<=9 and pH<=12:
        category = "Weaklyly basic"
     elif pH=<12 and pH=14:
        category = "Strongly basic"
     else :
        category = "pH out of range"
        
    return category