Really new to java

[Rcub]

I need to know how to say "but" or "therefore" in java? Would you use an if statement? if so how?

For example:

If player one has choosen one
therefore
Then player two cannot choose one

Again I am really new to java just trying to understand the basics

[Norm]

I think the logic you are talking about is the same in java as many other similar languages.
You use if statements to choose between different execution paths. You control the if statement by using boolean expressions.
See the tutorals:
Equality, Relational, and Conditional Operators (The Java™ Tutorials > Learning the Java Language > Language Basics)
Control Flow Statements (The Java™ Tutorials > Learning the Java Language > Language Basics)
Expressions, Statements, and Blocks (The Java™ Tutorials > Learning the Java Language > Language Basics)