Overly informal language

In academic writing, essays, etc., you should avoid using words associated with informal writing or informal speech. There is very often a more formal word that is more appropriate to the genre.

Things would be different if Sweden were a bigger country.

Things would be different if Sweden were a larger country.

The immigrants had a lot of trouble learning the language.

The immigrants had great difficulty learning the language.

A lot of the information in the report is wrong.

A great deal of the information in the report is false.

I guess I’ll apply again next year.

I suppose I will apply again next year.