according to

according to

used when we want to say that our information comes from some other person, book.

According to the timetable, the train gets in at 8.27

but it is not generally used with words like view or opinion, we use "in", in my opinion. Typical mistake: After my opinion....)

In my opinion, the rent's too high.


aches

Headache is a normal countable noun

I often get headaches.

heartache is a literary word for romantic sorrow or depression.


across and over

1. They can both be used to mean 'on or to the other side' of a line, river, road
Over is used for movements on or above water, but not in water.

How long would it take to swim across the river?

2. Only over is used for a movement to the other side of something high

When i last saw him he was climbing very slowly over the fence.

3. across and over can be used for movement inside an area
however, when we mean "from one side to the other of the area" or "movement in a three-dimensional space", we only use "across".

it took him six weeks to walk across the desert.