i want to optimize my website and among the highest traffic keywords I have singular and plural ones like "stock photos" and "stock photo". Both are important and have high traffic. 1) Do I have to optimize both or doing the plural one "Stock Photos" I'll get "Stock Photo" automatically? The same applies for stock images and stock image. 2) On the title tag should I use both keywords (stock photos and stock photo) or it can be considered spamming? I'd appreciated anyone's help. Cheers.