I did not go to his birthday party, but I bought him a present.

(The speaker gives the same emphasis to “not going to his birthday party” and “buying him a present”. Both ideas come in MAIN clauses.)

Although I did not go to his birthday party, I bought him a present.

(The speaker gives more emphasis to the second part of the sentence and less to “going to his birthday party” - Perhaps because it has already been mentioned.

Notes:

1. Although comes before a subordinate clause. It often sounds more FORMAL than a sentence with but.

2. Using although brings the two parts of the sentence together and relates them to each other. It also puts more emphasis on the main clause.

Whereas (vs although)

• Whereas Sam loves to study, her brother Josh never does his homework.
• Although Sam loves to study, her brother Josh never does his homework.
• Although it is summer, it is raining in England today.
• Although she didn’t have a lot of money, she bought a new dress for the party
• Cats are very clean animals, whereas dogs need to be washed once a fortnight.

Notes:

1. Whereas introduces a CONTRAST between two people or things which have different characteristics.
2. The clause with whereas can come first or later in the sentence.
3. Although does NOT suggest a similarity between two people or things.