minor prose tweaks

README.md

@@ -91,7 +91,7 @@ model = transformers.AutoModelForCausalLM.from_pretrained(
 )
 ```
 
-The model was trained first on 2048, and then an additional pre-training phase was included for sequence length adaptation to 8192. However, ALiBi further enables users to increase the maximum sequence length during finetuning and/or inference. For example:
+The model was trained initially on a sequence length of 2048. An additional pre-training phase was included for sequence length adaptation to 8192. However, ALiBi further enables users to increase the maximum sequence length during finetuning and/or inference. For example:
 
 ```python
 import transformers