grammar fix

the original writing isn't grammarly correct.

docs/developer/3.tutorials/5.non-fungible-tokens/2.what-will-we-build.md

@@ -3,7 +3,7 @@
 In this serires, we will create cw721-dapp project by using `Beaker` toolchain. 
 
 Before go into detail about code smart contract and dApp line by line, I will give an overview. So in previous chapter, I introduced CW721 - a specification for non-fungible tokens. Basically, we will store and instantiate CW721 contract then we can call contract address to create NFT. But it has one problem: <br />
-If you want generate many NFT, you must deploy same smart contract. Let's imagine you want to generate 1,000,000 NFTs, you must do same activities. So how to resolve this problem? We will build a cw721 factory contract, use cw721-base contract to create instance. So you only need deploy contract one time, and instantiate a new instance of this contract. Then you can interact with this instance to create own NFT.<br />
+If you want to generate many NFTs, you must deploy same smart contract repeatedly. Let's imagine you want to generate 1,000,000 NFTs, you must do same activities over and over again. So how to resolve this problem? We will build a cw721 factory contract, using cw721-base contract to create new instances. So you only need deploy the contract once, and instantiate a new instance of this contract. Then you can interact with this instance to create own NFT.<br />
 Integrate with previous series, we know how to create cw20 token. We will create a fixed-price-nft contract. It allows users to pay a fee in Cw20 tokens and get one new NFT in return.
 
 ![cw721-dapp](./cw721.png)