I am trying to create my custom spell checker for the UITextView. To show that a word is misspelled, I need to add the "red dotted line" under the misspelled word. To do that, here is what I thought would work - I create a dictionary which contains the values for the key NSUnderlineStyleAttributeName. However, what this does is, it does underline the characters but it does not have a dotted pattern. Also, setting the strokeColorAttribute also does not seem to have any effect. Here is my code - Code: NSMutableDictionary *misspelledAttributes = [NSMutableDictionary dictionary]; [misspelledAttributes setObject:[NSNumber numberWithInt:kCTUnderlineStyleThick|kCTUnderlinePatternDot] forKey:NSUnderlineStyleAttributeName]; [misspelledAttributes setObject:[UIColor redColor] forKey:NSStrokeColorAttributeName]; To set the attributes to a attributed string for a particular range - Code: NSMutableAttributedString *attrString = [self.textView.attributedText mutableCopy]; [attrString addAttributes:misspelledAttributes range:wordRange]; self.textView.scrollEnabled = NO; self.textView.attributedText = attrString; self.textView.selectedRange = NSMakeRange(NSMaxRange(range), 0); self.textView.scrollEnabled = YES; It would be great if someone could help me with this and point out what I am missing/doing wrong.