【Also】 , 【Too】 , 【Likewise】 , 【Besides】 , 【Moreover】 and 【Furthermore】 all denote in addition and are used when joining (not necessarily in the same sentence) one proposition or consideration to another.

【Also】 adds to a statement something that may be affirmed equally with what precedes.

• that where I am, there ye may be 【also】
  —Jn 14:3
• every simile ought not only to be well adapted to the subject, but 【also】 to include every excellence of description
  —Goldsmith

【Too】 is less formal than 【also】 , and adds with a lighter touch.

• like Twilight’s, 【too】 , her dusky hair
  —Wordsworth
• I can like now, and admire you 【too】 , sir
  —Thackeray

【Likewise】 is more formal and slightly more explicit than 【also】 ; it sometimes implies specific likeness or connection between the ideas which it unites.

• have I not seen—ye 【likewise】 may have seen— Wordsworth
• Greek, was your ambition 【likewise】 doomed to failure?
  —Browning

【Besides】 , 【moreover】 , 【furthermore】 introduce a statement which must be taken into consideration along with the matter which precedes.

【Besides】 usually introduces a statement that strengthens what has been said.

• his project is an excellent one; 【besides】 , it is likely to help a great many persons

【Moreover】 is more emphatic than 【besides】 , and often serves as a transitional word between sentences: it often implies that the stronger of two considerations is yet to be presented.

• the mountain was steep and rugged; 【moreover】 , its sides were coated with ice

【Furthermore】 is sometimes the most formal of these words; its chief use, however, is in a chain of additions where 【besides】 or 【moreover】 has already been used.

• he is well-liked; 【moreover】 , he is absolutely dependable; 【furthermore】 , there is no one who can take his place