I find myself a lot of times not able to communicate effectively. I frequently freeze trying to look for a word to put in the sentence I'm saying. I have trouble sometimes expressing what I'm trying to say in the correct manner. I just find myself a lot of times not knowing the correct terms to use in my language although I don't consider myself having a language problem.I read fluently and have no problem with written communication. I chat fluentyl with my chat programs but when it comes to verbal communication, I have this issue a lot of times .

Maybe your trying too hard.Being relaxed is the key to a nice flow in conversation.Even if you are feeling tense,portray self confidence and if you do it enough it will become authentic.Fake it till its real.

I took a sales seminar and communication was key to success.

Don't try to anticipate your response,be sure you are listening and giving your full attention to the speaker.

Relax,there is no need to rush your thoughts,slow down and if need be reiterate what the speaker has said.

Relaxation and confidence are key.

I have trouble sometimes expressing what I'm trying to say in the correct manner.
Communication is a two-way street. Don't think you are doing that task all alone. Ask your listener, "Quick! What's the word I'm searching for????"

No one is grading what you say. Conversation is not a performance. It doesn't have to be perfect. Engaging your listeners by asking for help with a word assures you that they are really listening to you, and people love to help -- whether it's to open a door for you or to help you carry something or to supply a word.

Communication is nothing but conveying your message correctly and completely. You may fumble with words at times when communicating. This can be improved often by reading (if possible read loudly) and make sure you understand each words meaning. Reading anything Newspaper, to magazines, to articles. You may find in a few months that you can speak comfortably without falling short of words.
All the best.
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This can be improved often by reading (if possible read loudly)
I suspect you mean "read aloud" (read out loud). Reading loudly (with a loud voice) will not improve your command of English or raise your confidence level.