1. If Hitler had won the war, the German Language would be our lingua franca.

His defeat was because he chose a two-prong war of the West and the Soviet Union.

He was on the verge of defeating UK, had destroyed France, Belgium, Czech and basically all the countries in Europe

2. He signed a non-aggression pact with the Soviet Union in the East just to have breathing space.

However, most of the lands he conquered in the East were being land-grabbed by the Soviets which he reluctantly agreed so as to keep them happy.

What changed his mind?

3. Oil from the Balkans were been grabbed by the Russians and he felt he had already defeated the UK (The last power in the west). He thought he could move his troops to the East and finish off the Soviet quickly.

He counted his chickens before they were hatched.

4. The two-prong war meant his troops became battle-strained.

Japan, who were friends were supposed to attack Vladivostok to finish off the Russians but they instead chose to attack U.S (which confused Hitler). This action officially drew the U.S into the war

5. The Americans were friends with UK but the American public did not want to be involved in any war. Anyways they became involved...

To recap, if he had finished off UK, invaded and rested, he would have eventually controlled the World.

I would have been typing this in German