Explanation

See is a verb here.

See means ملنا یا ملاقات کرنا

Saw is the second form, seen is the third form of see.

We generally use first form after ‘to’.

‘to’ is a preposition here.

Our friends often come to see us means ہمارے دوست اکثر ہم سے ملنے آتے ہیں۔