My fFirst eEntry My First Entry

Many writers capitalize the important words in the titles of their posts.

Currently, I am student in class 12th. You'll need the indefinite article the first time you introduce a new noun: "Currently, I am a student in class 12." Currently, I am student in class 12th. You'll need the indefinite article the first time you introduce a new noun: "Currently, I am a student in class 12."

Currently, I am a student in class 12th. Currently, I am a student in class 12th.

Currently, I am student in class 12ththe 12th grade. Currently, I am student in the 12th grade.

this is American English; I'm aware that other folks say it differently

Currently, I am student in class 12tha 12th grader / a senior in high school. Currently, I am a 12th grader / a senior in high school.

These are two other ways we say this in the US. Each of the four high school years have a name (freshman, sophomore, junior, and senior). We use the same names for a four year college program, so that is why we add "in high school." (Sorry if this is useless info for you.)

Currently, I am a student in class 12th12th grade. Currently, I am a student in 12th grade.

I am not sure what you mean by "Class 12th"—if you mean 12th year in school, it should be "12th grade," at least in the United States.

I am studying multiple languages, which are: English, French, Sanskrit, Bengali. I am studying multiple languages, which are: English, French, Sanskrit, Bengali.

You need a complete sentence before a colon. In this case, no punctuation is needed after the copula "are". Example: I have many pets, which include cats, dogs, lizards, and snakes. Example: I have four types of pets: cats, dogs, lizards, and snakes.

I am studying multiple languages, which are: English, French, Sanskrit, and Bengali. I am studying multiple languages, which are: English, French, Sanskrit, and Bengali.

Also add 'and' before the last word you're listing.

I am studying multiple languages, which are: English, French, Sanskrit, and Bengali. I am studying multiple languages: English, French, Sanskrit, and Bengali.

I am studying multiple languages, which are: English, French, Sanskrit, and Bengali. I am studying multiple languages: English, French, Sanskrit, and Bengali.

I am studying multiple languages, which are: English, French, Sanskrit, and Bengali. I am studying multiple languages: English, French, Sanskrit, and Bengali.

But I can understand an addition of Tamil, Hindi, Odia and a little bit of Gujarati. But I can understand an addition of Tamil, Hindi, Odia and a little bit of Gujarati.

Better: But I can also understand Tamil, Hindi, Odia, and a little bit of Gujarati.

But I can understand an addition of Tamil, Hindi, Odia and a little bit of Gujarati. But I can understand Tamil, Hindi, Odia and a little bit of Gujarati.

But I can also understand an addition of Tamil, Hindi, Odia, and a little bit of Gujarati. But I can also understand Tamil, Hindi, Odia, and a little bit of Gujarati.

ButIn addition, I can understand an addition of Tamil, Hindi, Odia and a little bit of Gujarati. In addition, I can understand Tamil, Hindi, Odia and a little bit of Gujarati.

This is one way to keep the phrase "in addition" in your sentence. I think with this construction you don't need "but" because instead of contrasting the languages you are studying with the ones you only understand, you are adding this information about what you can do.

But I can understand an addition of Tamil, Hindi, Odia and a little bit of Gujarati. But I can understand Tamil, Hindi, Odia and a little bit of Gujarati.

I do not know what you mean by "an addition of"... Maybe you meant "in addition"? If so, you should say: "But, in addition, I can understand Tamil..."