Wish and If only

When we want something to be different than it is we can make sentences with wish or if only.

Wish

Present

subject	wish	subject	past simple
I	wish	I	had	a million dollars.
I	wish	I	could	speak Chinese.
I	wish	she	lived	nearer.

It is the same construction as the second conditional. As with the second conditional it is an unreal situation.
Also as with the 2nd conditional, when we use the verb to be we can use the were form for all forms of the verb.

subject	wish	subject	past simple
I	wish	she	were	here.
I	wish	I	were	rich.

Past

When we want something to have been different in the past we use the following construction:

subject	wish	subject	past simple
I	wish	I	had gone	out last night.
I	wish	I	had seen	that film.
I	wish	I	hadn’t eaten	so much.

It is the same construction as the third conditional. Like the third conditional it refers to a situation in the past which can’t be changed.

If only

If only has basically has the same meaning although we use it when we are slightly more desperate.

Present

If only	subject	past simple
If only	I	had	a million dollars.
If only	I	could	speak Chinese.
If only	she	lived	nearer.

As with wish, if only has the same construction as the second conditional, so it is an unreal situation and when we use the verb to be we can use the were form for all forms of the verb.

Past

If only	subject	past simple
If only	I	hadn’t gone out	last night.
If only	I	had seen	that film.
If only	I	hadn’t eaten	so much.

As with wish, it has the same construction as the 3rd conditional and so refers to a hypothetical situation in the past which can’t be changed.