Tom's teacher doesn't have full evidence to prove if his student is telling the truth or not, so he chooses to accept what Tom is saying, his version of the facts... The teacher gives Tom the benefit of the doubt. =)

The "doubt" is the doubt over someone's honesty. They could be telling the truth or lying, but you choose to accept the positive possibility (benefit) and assume they are telling the truth. So when you accept someone's story as true when it could equally be false, you "give them the benefit of the doubt". This is a good phrase to remember!

'Give someone the benefit of the doubt' means 'to make a judgment in someone’s favor when the evidence is neither for nor against the person.' Although the teacher was not sure that Tom's explanation was correct or that he told the truth, she decided to show good opinion of him. This is what the judge usually does. He usually gives the accused the benefit of the doubt (= regards him as innocent until proven otherwise.)

Doubting his explanation is BETTER than not believing his explanation at all. 1. doubt= partial disbelief/ partial belief 2. benefit= favor The teacher is doing him a favor by doubting him rather than disbelieving him entirely.

It is an expression that means he believed him. The teacher did not believe or trust whatever Tom was saying (the teacher doubted it), however Tom's explanation may be true so the teacher assumed that what Tom said was true. For example: "Although he found it hard to believe Tom's explanation, the teacher decided to believe his explanation even though he doubted the explanation." That is a hard expression to explain, and I don't think I explained it very well, hopefully someone else can add more.