よく見張ってなければだめよ。
Sentence Analyzer
English Translation
        You must keep your eyes open.
    
Furigana
        よく見張 ってなければだめよ。
    
Romanji
        Yoku mihatte nakereba dame yo.
    
Words
            
                良く
            
            
                (よく)
            
        
        
            nicely; properly; well; skillfully; skilfully; frequently; often
        
    
            
                見張る
            
            
                (みはる)
            
        
        
            to stand watch; to stand guard; to look out; to open one's eyes wide
        
    
            
                無い
            
            
                (ない)
            
        
        
            nonexistent; not being (there); unpossessed; unowned; not had; unique; indicates negation, inexperience, unnecessariness or impossibility; not ...; to not be...; to have not ...
        
    
            
                駄目
            
            
                (だめ、ダメ)
            
        
        
            no good; not serving its purpose; useless; broken; hopeless; wasted; in vain; purposeless; cannot; must not; not allowed
        
    
            
                よ
            
            
                (よ)
            
        
        
            indicates certainty, emphasis, contempt, request, etc.; used when calling out to someone; used to catch one's breath or get someone's attention; yo!