Linking words

But and however can contrast ideas, but they are used differently.
es. I learnt French easily, but I didn't like my teacher
I learnt French easily. However I didn't like my teacher

So is used to express the result of the statement before. It usually goes in the middle of a sentence, whereas therefore goes at the beginning of a new swntence and it is more common in writing.
es. It started to rain, so we stopped playing tennis

Because express the reason or cause of something. It goes at the beginning or in the middle of a sentence; it is stronger tha as and since and it can be used to negin the answer to a question beginning with "Why".
es. We stopped palying tennis beacuse it started to rain

While is a conjunction, and is followed by a clause (subject+verb). if you say "X happened while Y happened", it means X and Y happened at the same time.
es. I met Peter while I was studying at university

During is a preposition, and it is followed by a noun. It has a similar meaning to while.
es. I worked on a farm during the holidays.
The noun after during expresses an activity that takes time.
es. during the film/lesson/afternoon
While and during answer the question When?

For is a preposition, and answer the question How long? It is followed by a time expression.
es. I lived there for 3 years.

In order to, so that are stronger than "to" and "so"
es. In order to be really fit, I've been training every day

Such means "as much as this" and it can be used to talk about cause and effect.
es. He was such a slow walker that we arrived late
You can omit "that".
You can use "such" after "because".
es. Her teacher sent her home because she was such a naughty child
"Such" is followed by:
- a/an+adjective+noun es. such a rich man
- a/an+noun only es. such kindness
- the expression "a lot of" with or without a noun es. such a lot of people

Enough means "sufficient, the right quantity". Too means "more than enough". they are followed by:
- to+infinitive es. too heavy to carry/strong enough to carry
- for something/someone es. too small for me