Difference between American English Writing and British English Writing

Grammar:

This topic includes the grammatical difference in British and American writing. We need to consider these grammar points while making document for the audience based in US or UK.

Use of Tense:

For an action started and finished at a specific time in the past-

British English	American English
Use Present perfect tense (have/has + past participle)	Simple past tense OR Present perfect tense
I have eaten my apple.	I ate my apple
I haven't see Jenny in the party.  Have you seen her?	I didn't see Jenny in the party. Did you see her?
Jenny has gone home.	Jenny went home.

In British/American English, people also use the words like- already, just and yet to talk about an action started and finished at a specific time in the past. For example:-

1.  Jenny has just gone home.
2.  I have already seen the movie.
3.   Jenny didn’t come yet.

Use of Verbs:

If you check the forms of verbs, you will find few differences between simple past and past participle forms in American and British English. Irregular forms of verbs are rarely used in American English whereas irregular and regular both the forms can be used in British English. Exceptional case in American English for irregular past forms of verbs are burnt, dreamt and spoilt.  

For example:

British English	American English
Infinite Simple Past Past Participle Get Got Got Bust Bust Bust Burn Burned/Burnt Burned/Burnt Learn Learned/Learnt Learned/Learnt Dream Dreamed/Dreamt Dreamed/Dreamt Saw Sawed Sawn Wake Woke Woken	Infinite Simple Past Past Participle Get Got Gotten Bust Busted Busted Burn Burned/Burnt Burned/Burnt Learn Learned/Learnt Learned/Learnt Dream Dreamed/Dreamt Dreamed/Dreamt Saw Sawed Sawn/Sawed Wake Woke/Waked Woken

Prepositions:

In both the writing, prepositions are used differently. One of my friends told me few tips to recognize the writing by checking the use of preposition. I would also like to share it with my writer friends. Here are few examples:

1.    For the word “Talk”- In British writing, they prefer using the preposition “to” whereas in American writing they prefer using “with”. 
2.    For Time span- In British writing, they prefer using the preposition “to” whereas in American writing they prefer using “through”.
3.  For time expressions (weekends) - In British writing, they prefer using the preposition “at” whereas in American writing they prefer using “on”.
4.   For universities or other institutions- In British writing, they prefer using the preposition “at” whereas in American writing they prefer using “in”.

S. No.	British English	American English
1	I will talk to John	I will talk with John
2	January to December	January through December
3	We like to party at weekends.	We like to party on weekends.
4	I have done technical writing course at System Domain.	I have studied English Literature in Bangur University.

Note: In American English, avoid using preposition after few verbs. For example:-

1. US Writing: John claimed the insurance.
2. UK Writing: John claimed for his insurance.

My job involves writing. I always get confused while writing for UK/US based audience. I keep browsing on search engines to make my concept clearer. In these posts, I am making effort to put light on few differences between UK and US English writing.  

For more detail, my writer friends can view the link-

http://en.wikipedia.org/wiki/Comparison_of_American_and_British_English#Grammar