be welcome to (something)
To be expressly or freely permitted to have, use, or do something. You're welcome to the spare bed if you want to spend the night here. They're welcome to change the color if they are that unhappy with it.
welcome to (do something)
1. adjective Expressly permitted or encouraged to do something. I just don't think it's possible to get this motor started, but you're welcome to try. Why are you so upset? You said I was welcome to take the car out whenever I wanted!
2. verb To permit or encourage someone to do something. In this usage, a noun or pronoun is used between "welcome" and "to." If anyone doubts my research, I welcome them to prove me wrong. We would like to welcome everyone and their families to join us for our annual company picnic this weekend.
welcome to (something or some place)
1. A greeting said to someone upon joining, entering into, or arriving at something or some place. Ah, Mr. Smith—welcome to Denver! How was your flight? Welcome to the team, Sam. Everyone is looking forward to working with you. Welcome to the annual county fair! We hope you have a wonderful time.
2. To give someone a cordial, hospitable greeting to something or some place. In this usage, a noun or pronoun is used between "welcome" and "to." The diplomat was at the airport to welcome the foreign dignitaries to the country. Please join me in welcoming Sarah to the company as our new VP of Sales.
welcome someone to something
to greet someone who has come into something or some place. I am very pleased to welcome you to Adamsville! They welcomed us to the party and showed us where to put our coats and hats.