2(a). I think my brother and I are very similar. CORRECT 2(b). I think my brother and me are very similar. INCORRECT 2(c). I think my brother and myself are very similar. INCORRECT It is not correct to use an OBJECT pronoun or a REFLEXIVE PRONOUN before a verb. You have to use a SUBJECT pronoun before a verb. You have to say "I am". You should NEVER say "myself am" or "me am". That is not correct! Whenever you are in doubt, here is a simple trick: try removing the other subject. In this case, the other subject is "my brother" so remove the words "my brother and" from your sentences, and try reading the sentences again. Now you will have: 2(a). I think I am very similar. CORRECT 2(b). I think me am very similar. INCORRECT 2(c). I think myself am very similar. INCORRECT "I am" is correct. "me am" is not correct. "myself am" is not correct. Hope this makes it crystal clear. Note: In colloquial use, it is very common for uneducated native speakers of English to use object pronouns as subject pronouns when talking about two or more subjects. It seems to have become colloquially acceptable in casual conversation, but it is incorrect. Unless they have studied the grammar of their own language, many native speakers don't even seem to realise that they're saying it incorrectly. i.e. It is very common to hear uneducated native English speakers saying things like: "me and my sister are going to a party" or "my Dad and me will give you a lift home". Both of those sentences are wrong, because they both feature object pronouns being used incorrectly as subject pronouns. What they should actually be saying is: "my sister and I are going to a party" and "my Dad and I will give you a lift home". The reason for this is that it is not correct to use "me" as a subject pronoun. We don't say "me am going" or "me will". We should say "I am going" and "I will".

1(b) is almost correct; it should be "Are you similar TO or different from your brother?" 2(a) is correct; the others are not. Explanations: 1 - In English, we say, "Are you similar to your brother?" and "Are you different from your brother?" When we use two words that have different prepositions, we have to use both of them (with their respective nouns) in order to avoid confusion. This is proper grammar. 2 - A good way to remember this rule is to cut off the first half of the sentence. Example: "My brother and / I will go to the store." --> "I will go to the store." You would not say "My brother and / me will go to the store." because "Me will go to the store." doesn't make any sense. In the same way, "Myself will go to the store." also doesn't make sense. The way to use "me" and "myself" would be these example sentences: (Me) - "She took me to the store." "They gave me a present." "You hurt me." (Myself) - "I told myself I wouldn't eat that cupcake." "I hurt myself falling down the stairs." [or, less common but still correct:] "I myself believe the world is round." So, to recap, "me" receives. "Me" is the object of a sentence. "I" does. "I" is the subject of a sentence. "Myself" is used when you are doing something to yourself, but also when you are putting emphasis on your own words. (like "I myself hate cockroaches.") Hope that helps!