Yes, you can. Every planning application submitted to a local authority must undergo a period of public consultation which varies in length between three and eight weeks. Most councils publish details of planning applications on their websites.

There are a number of ways to do this:

If you are a neighbour affected by a planning application the local planning authority will either notify you directly or display a site notice on or near the land to which the application relates.
You could contact the planning offices of your local authority to involve yourself in the consultation process

The local planning authority may offer a service on its website
You are allowed to attend planning committee meetings to hear applications being considered

You are also allowed to have your say at these meetings but you must notify the council in advance of the meeting

As a result, the range of objections that can be made is wide and varies from council to council.