If then else syntax error

Hi,

I have a column called 'Sentiment' with numbers between 0 and 1. 

I want to add a new column based on the condition as follows:

[Sentiment] <0.5 then "Negative"

[Sentiment] =0.5 then "Neutral"

[Sentiment] >0.5 then "Positive"

I know you can add a conditional column in PowerBI. 

But at the beginning I wrote a query like this:

If [Sentiment]< 0.5 then "Negative"
else
If [Sentiment] = 0.5 then "Neutral"
else
If [sentiment] >0.5 then "Positive"
else NULL

There is an error message says Token Eof expected. 

What should be the correct query for this?