Linking words and phrases in English (also called ‘connective’ or ‘transition’ words) are used to combine two clauses or sentences presenting contrast, comparison, condition, supposition, purpose, etc.
They enable us to establish clear connections between ideas.

Most linking words can either connect clauses within a sentence, or start a sentence to form a link with the previous statement.

Note : A clause is a group of words that includes a subject and a verb.
 The following sentence contains two clauses:
 She lives in Mexico because she likes the climate.

Below you will find some examples of linking words and how to use them. This is not a comprehensive list.
You may want to add your own linking words and phrases.

Examples of linking words within one sentence:

Linking WordsExamples of Use
As long as
provided (that)
providing
You can take my car as long as/provided (that)/providing you don’t damage it.
(I will lend you my car on condition that you don’t damage it.)
Although/even thoughHe lives in a small house although he is a millionaire.
(In spite of the fact that he is rich, he lives in a small house.)
Because
Since
She hurried because she was late.
I’ll apply for the job 
since you’re not interested.
Even ifHe is poor and has no house, but even if he had money, he wouldn’t buy a house.
(Supposing he had the money, he still wouldn’t buy a house.)
In caseTake an umbrella in case it rains.
(It might rain, so it’s a good idea to take an umbrella.)
In spite of/DespiteIn spite of/despite the rain, she walked to the station.
In spite of/despite being blind, he walked to the station.
(without being affected by the rain or by being blind.)
NotwithstandingHugo won the race notwithstanding his lack of training.
So thatJulie arrived early so that she could help her colleagues.
(She arrived early for the purpose of helping her colleagues.)
UnlessThe radio won’t stop unless you turn it off.
WhateverYou can count on me whatever you decide to do.
(No matter what your decision is, you can count on me.)
WhereasTom is rich, whereas Jack is poor.
(Tom is rich; in contrast Jack is poor.)
WheneverI will lend you my car whenever you need it.
(No matter when you need my car, I will lend it to you.)
WhereverMy thoughts will be with you wherever you go.
(No matter where you go, my thoughts will be with you.)

Examples of linking words that connect two separate sentences or two clauses:

Note : If linking words start a sentence, they are followed by a comma.
When they are used to connect two clauses, a semi-colon is placed at the end of the first clause.
A comma is often used after the linking word(s).

Linking WordsExamples of Use
As a result
Consequently
Therefore
– Prices were reduced by 20%. As a result, sales increased.
– The company is expanding. Consequently, there are jobs on offer.
– A hurricane has been announced. Therefore, air traffic will be disrupted.
Besides
Furthermore
In addition
Moreover
– The trip is too expensive. Besides, I don’t really like hot weather.
– Computers are cheaper nowadays; furthermore, they are lighter.
– You haven’t paid the rent yet.  In addition, you owe me money.
– The report is badly presented. Moreover, it contains inaccuracies.
For instance
For example
– There are several problems to consider; for instance/for example, there is a lack of public transport.
Conversely
On the contrary
On the other hand
– Northern European countries had a great summer.
  On the contrary/conversely, southern Europe had poor weather.
– Laptops are convenient; on the other hand, they can be expensive.
However
Nevertheless
Nonetheless
– The hotel was open. However, nobody came to the reception desk.
– He had severe injuries; nevertheless, he completely recovered.
– The weather was bitterly cold. He went hiking nonetheless.
Subsequently
Afterwards
– The castle was sold.
  Subsequently/afterwards it became a hotel.
In the same way
Likewise
Similarly
By the same token
– Alex enjoys telling jokes;
in the same way /similarly / likewise, his son adores funny stories.
– Teenagers should be more respectful;
by the same token, parents should be more understanding.
To sum up
Briefly
To conclude
In conclusion
– I’ve covered the main events of the year.
  To sum up / briefly, our team is now one of the best in the world.
  To conclude / in conclusion, I want to wish you all a very happy holiday season.