1) know\knows famous architect. 2) is\are fairly old. 3) defended our country in 1941-1945. 4) work\works in a bank. 5) speak\speaks russian. 6) speak\speaks other languages. 7) visited st petersburg last year (some years ago)

1)I know a famous architect.
2) it is quite old.
3) he defended our Motherland in 1941-1945.
4) he works in a Bank.
5) she speaks Russian.
6) they speak other languages.
7) last year I visited Saint-Petersburg (several years ago)