[Grammar] which I believe is? or which is I believe?

[kkknn]

Hello there!

I've got a problem with the following sentences.

The most important thing is motivation, which I believe is the key to learning english.

Should I say "which is I believe" instead of "which I believe is"?

Here are some other sentences.

1. In my constituency I have RAF Leuchars, which I believe is the last air defence base to maintain the quick reaction alert.

2. Unless the Israeli Government accept the package by the end of the present Knesset session, which is I believe 29 July, it looks like staying that way.

I tried to look up the grammar rule in some books and failed.
Now I'm turning to you! please help me!

 

[billmcd]

The most important thing is motivation, which I believe is the key to learning english.
Should I say "which is I believe" instead of "which I believe is"?
Either is OK but use commas in: "which is, I believe, ". But I like your original example.

1. In my constituency I have RAF Leuchars, which I believe is the last air defence base to maintain the quick reaction alert. I don't really understand the context here but it looks OK. Maybe it should read "a quick reaction alert".

2. Unless the Israeli Government accept the package by the end of the present Knesset session, which is I believe 29 July, it looks like staying that way.

"accepts" and "it looks like it will stay that way"