Were VS Was

[ligalako]

Hi,
I encounter a few sentences in which I saw the verb Were instead of the verb Was. You can see below 2 of them.
will snap easily, as though it were a twig
I wish Christian were my boxing teacher - why not was

Can you guide me what is the rule for this cases? When do I use Were instead of Was?
Thanks

[Jazmet]

One explanation -

For hypothetical situations - Situations that are not true but are wished for. Ex - I wish I were the President of India.

[jnelson0612]

Jazmet is correct. Please see this thread about the hypothetical subjunctive mood: subjunctive-subject-verb-agreement-t12915.html